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August 26th, 2013

Practice Variations and Quality: Ask the “Uber” Expert

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In response to recent reports of variation in practice and outcomes of elective PCI, CardioExchange’s Rick Lange asks Harlan Krumholz to elaborate on what constitutes high-quality decision making.

Three interesting studies recently released showed:

1. Physicians in New York State perform twice as many cardiac catheterizations per capita as those in Ontario, and the increased use of cardiac catheterization in New York relative to Ontario (regions with very different payment systems) is primarily the result of selecting more patients at low predicted probability of obstructive CAD.

2. Medicare Advantage (i.e., capitated payment) patients have lower rates of elective angiography and PCI than Medicare fee-for-service (FFS) patients. Furthermore, elective procedure rates vary widely (as much as 3–4-fold) by geographic region for both capitated and FFS payment patients.

3. New PCI programs from 2004 to 2008 did not improve timely access for patients with STEMI.  These new programs were more likely than not to be introduced in areas that already had a PCI program, near populations with higher rates of private insurance, in states that had weak or no regulation of new cardiac cath labs, and in wealthier and larger hospitals.

In a “take no prisoners” editorial, Harlan Krumholz (also editor-in-chief of CardioExchange) admonishes that variations in practice should “disturb physicians…. because of the possibility that such variations do not optimally serve the best interests of patients.”  He’s not bothered by variation in practice, “provided that variation is based on patient clinical differences and preferences rather than on other factors such as payment method, geography, or system proclivities.”   He urges “high-quality decision making.”

So, Harlan….

RL: What exactly is “high quality decision making?” Who decides? Can it be measured?

HK: In my JAMA editorial, I called for us to set standards for high-quality decisions, develop metrics for assessing the quality of decisions, and promote effort to ensure that we are promoting high-quality decisions by our patients. Since many decisions seem highly influenced by who provides the care, I wonder if we can say that the patients are guiding the decisions. By the way, I am talking about non-emergency decisions — when there is time for deliberation, and patient preferences ought to dominate – like the choice between PCI and optimal medical therapy for stable CAD.

So what does constitute a high quality decision? Good decisions are informed, value-concordant decisions. Patients can be overwhelmed by information, but do they know the key information? We conducted a study years ago that showed that most patients undergoing elective PCI incorrectly thought that the procedure would extend their life or help them to avoid a heart attack. More recently, a similar study essentially found similar results. If patients have misconceptions, they cannot make high-quality decisions. “Value-concordant” means that we do not force a decision on patients but ensure that their choice is consistent with their values, preferences, and goals. For many decisions, there is not a single right choice. The choice is among strategies that all have risks and benefits. Patients need to pick the one that fits them best.

There are best practices in decision-making — and I think we can start teaching them. And ultimately we may be able to measure whether a good decision is achieved — and to what extent.

What’s important here is that we would be assessing the process by which the decision was made — not the decision. We are not determining if patients made the “right” choice (especially if that is defined as what we would do) — but whether they were able to understand the key information and decide based on what is important to them.

Also, the decision should not be judged by the outcome. Good decisions can be followed by poor outcomes. And outcomes after decisions are probabilistic – that is the point. We can almost never guarantee an outcome in these types of decisions — so how people choose depends on their risk tolerance and how they feel about the possible interventions — what they may cost (yes, that is a real consideration for many people), and what may happen.

The tricky part is that sometimes patients are fearful and do need some coaching — but I believe that coaching ought to be an effort to give them the courage to determine what they want to do, not to coax them into doing something that they do not want to do.

The impression of patients after the decision may not be a good metric because most people, subject to cognitive dissonance, will express that they did the right thing — assuming that the result was not disastrous.

RL:  You advocate informing and guiding patients through decisions. On average, physicians spend 8 minutes with each patient. How does one create “well-informed” patients and understand patient preferences in that setting?

HK: We need to develop a different approach. Doctors are paid too much to spend the time that is necessary to educate patients. We need a team to participate — and we need to find ways to get people informed in a way that is affordable.

RL: What do you do when the patient’s — and sometimes referring physician’s — preference is at odds with evidence-based medicine? For example, the asymptomatic, low-risk patient who demands a coronary calcium score or myocardial perfusion scan. What is the “high-quality decision” in that setting?

HK: I do think that there are some decisions that are out of bounds. For example, if a patient asks me to give him cyanide — or to do a procedure that has no supporting evidence. We are talking about how choices are made among strategies that are all within bounds. The problem is that patients are often told there is only one good choice when, in fact, there are more — and reasonable people could choose among them. We need to be clear about what is within bounds and what is not.

August 26th, 2013

New Subcutaneous ICD Said to Pose ‘Existential Crisis’ for Older ICDs

Last year the FDA approved Boston Scientific’s subcutaneous ICD (S-ICD), the first ICD that doesn’t use transvenous leads. Those leads are the source of many sophisticated pacing features in today’s ICDs, but they are also the main source of ICD-related complications.

FDA approval of the S-ICD was based on a pivotal trial designed to assess the device’s safety and effectiveness. Results of the trial have now been published in Circulation. In this nonrandomized trial, the S-ICD was successfully implanted in 314 patients out of 321 in whom the implantation was attempted.

The S-ICD easily met the prespecified primary safety and efficacy endpoints:

  • Primary safety end point (180-day complication-free rate): 99%. The lower confidence limit of 87.9% surpassed the prespecified performance goal of 79%.
  • Primary effectiveness end point (the acute induced VF conversion rate at the time of implantation): 100%, achieved in all of the 304 patients who underwent the full testing protocol, “far exceeding” the performance goal of 88%. A total of 17 patients were not evaluated for effectiveness, but even if all were deemed failures, the acute VF conversion rate would still have been well above the lower confidence limit.

During the course of followup there were 38 episodes of VT/VF in 21 patients. These were all successfully converted. Overall, 13.1% of patients received an inappropriate shock.

The results, write the authors, “demonstrate that the S-ICD System is safe and well tolerated as a chronically implanted ICD and is effective in terminating both induced and spontaneous VT/VF.”

In an accompanying editorial, Leslie Saxon writes that the appearance of the S-ICD “poses a significant existential crisis for the now middle-aged standard, transvenous, and fully featured ICD.” The S-ICD “is pared down to 1 essential meaning, purpose, and value: ventricular arrhythmia defibrillation.”

Although the available data on the S-ICD “are reassuring and comparable to transvenous ICD success rates,” she notes that “the overall number of treated episodes is incredibly small in comparison” with standard ICDs, which also have much longer followup data. In addition, “a significant limitation from a clinical learning and safety advisory perspective” is the lack of remote monitoring capability.

Saxon nevertheless suggests that a “significant percentage” of potential ICD patients may be candidates for the S-ICD, including those with “prohibitive vascular access issues” and those at high risk for major infection associated with a transvenous lead.

In an interview, Saxon said that although the S-ICD is a genuine advance in defibrillation technology, it also represents something of a throwback, as it appears to contradict “the constant evolutionary course of technology” in which more features and capabilities are packed into increasingly small spaces with each subsequent generation of technology.

 

August 26th, 2013

Missing Data And The ATLAS ACS 2-TIMI 51 Trial

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In a recent Viewpoint in JACC two members of the FDA’s Cardiovascular and Renal Drugs Advisory Committee, Mori Krantz and Sanjay Kaul, write about the problem of missing data in the ATLAS ACS 2-TIMI 51 Trial and consider some of the larger implications of missing data in clinical trials. One of the authors, Sanjay Kaul, agreed to answers questions about the topic from CardioExchange’s Harlan Krumholz.

HK: What is the issue with the missing data in ATLAS and why is it important?

SK: The amount of missing data, especially lack of vital status information, is inordinately large in that it challenges the interpretation of the data. Furthermore, there is potential for “informative censoring,” i.e., patients who are dropping out of the study because of a bleeding side effect from rivaroxaban might also be at risk for experiencing the thrombotic events (primary endpoint). This differential dropout together with missing information regarding thrombotic events from these patients might amplify treatment differences in favor of rivaroxaban.

HK: How do you think the missingness problem in ATLAS should affect our view of the drug?

SK: Missingness contributes to lack of confidence in the data being reliable. However, missingness is not the only issue that should affect our view of the drug. The data are not coherent in the sense that the 2 doses of the drug have a different effect on the components of the primary endpoint (2.5 mg dose reducing CV death but not MI; 5 mg dose reducing MI but not CV death). In addition, there is little external support for incremental benefit with the use of novel anticoagulant agents on top of dual antiplatelet therapy. Finally, even if missingness was not a major concern, the results are not ‘statistically persuasive’ to justify an ACS indication on the basis of a single trial (the FDA Guidance requires 2 successful trials or one trial with persuasive evidence plus confirmatory evidence).

HK: Should ATLAS results be used in meta-analyses – or do you have concerns about whether we can rely on them?

SK: Although missingness challenges the interpretation of the ATLAS results, it does not necessarily invalidate them. If the ATLAS data end up being used in a meta-analysis, I would like to see a sensitivity analysis addressing the impact of the ATLAS results on the overall pooled estimates. I would question the strength of evidence if the overall evidence is driven by the ATLAS results.

August 22nd, 2013

Expert Perspective: Remote Ischemic Preconditioning for CABG

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Dr. Zhe Zheng and Dr. Shengshou Hu, of Fu Wai Hospital in Beijing, discuss findings from a randomized trial, conducted in Germany and published in the Lancet, of remote ischemic preconditioning before coronary artery bypass graft surgery. (See CardioExchange’s news coverage here.)

THE LANCET STUDY

Thielmann and colleagues randomized 329 patients with triple­vessel CAD undergoing elective, isolated first-time CABG to receive remote ischemic preconditoning (rIPC; consisting of 3 cycles of inflation of a blood-pressure cuff for 5 minutes, followed by 5 minutes of reperfusion) or no preconditioning. The rIPC group had significantly lower serum cardiac troponin I (cTnI) levels in the first 72 hours after CABG. Clinical benefits were not evident at 30 days, but rIPC was associated with significantly lower rates of MI and all-cause mortality at 1 year. The rIPC group’s hazard ratio for 1-year all-cause mortality, compared with the control group, was 0.27 (95% CI, 0.08–0.98; P=0.046).

EXPERT PERSPECTIVE

Reperfusion injury may be an important therapeutic target for improving clinical outcomes after acute myocardial infarction or open-heart surgery. Ischemic preconditioning, whereby the heart is subjected to brief cycles of ischemia and reperfusion, may help to limit damage from acute ischemia and reperfusion injury.First reported by Murry and colleagues in a dog model, ischemic preconditioning was then replicated in multiple in-vivo models. Mediators and pathways such as transcription factors, oxidative stress, humoral factors, neuronal communication, and systemic-inflammatory or apoptosis responses may interact dynamically in ischemic preconditioning, although the precise mechanisms are not yet clear.

Clinical application of ischemic preconditioning has been restricted to certain cardiovascular surgical procedures, primarily operations in which the ischemic period is predictable. In the past decade, randomized controlled trials of the effects of rIPC have had variable results (e.g., J Am Coll Cardiol 2006, 47:2277; Circulation 2007, 116:I-98; Heart 2009, 95:1567; J Thorac Cardiovasc Surg 2012, 144:178; and J Thorac Cadiovasc Surg 2013, in press). Postoperative cTnI levels, creatine kinase-MB levels, and inotropic requirements during the initial days after surgery have been identified as markers of myocardial protection, but the evidence on mortality and prognostic factors is extremely limited. Besides, this simple and safe technique has rarely been used during CABG, at least outside the context of research.

The study by Thielmann and colleagues provides useful perspective for further study, and even clinical application, of rIPC. Their intention­to­treat and per­protocol analyses both confirm the protective benefits. We know that the trial participants were low-risk patients, and the authors openly state the study’s limitations (single center, endpoints not intuitively related to cardioprotection, small number of secondary endpoints, etc.).

Notably, however, differences in study protocols, potentially confounding comorbidities, and surgical procedures might be responsible for inconsistent findings across the various published trials. For example, previously reported strategies for rIPC vary in the duration for cycles of ischemia and reperfusion (1, 5, or 10 minutes), as well as locations in the left upper arm, the right forearm, the lower limb, or the common iliac artery (according to the types of surgery and patient groups).

The findings from Thielmann and colleagues are certainly noteworthy, even though trigger mechanisms and possible pathways must be explored in further studies. Larger trials also will need to test the effectiveness of rIPC in surgical revascularization settings and in patients with comorbidities that affect tolerance of ischemia–reperfusion.

JOIN THE DISCUSSION

What’s your view on remote ischemic preconditioning, in light of findings from the trial in Germany and analysis from Dr. Zheng and Dr. Hu?

August 21st, 2013

Kaiser Program Yields Big Improvements in Hypertension Control

A large percentage of the 65 million people with high blood pressure in the United States do not know they have hypertension or have not succeeded in controlling their hypertension. Although many programs have been proposed, there is little evidence that any method can produce long-term improvement in hypertension control.

Now, in a paper published in JAMA, researchers at Kaiser Permanente report the outcomes achieved with a large-scale multipronged approach to hypertension control. The program included a comprehensive hypertension registry and the development and sharing of performance metrics. Electronic medical records were used to encourage optimal treatment, while patients were offered free follow-up visits with medical assistants and simplified medication regimens, including the use of single-pill combination therapy. Physicians were encouraged to use algorithms derived from evolving evidence.

The Kaiser Permanente Northern California (KPNC) hypertension program started with 349,937 patients  in 2001 and increased to 652,763 patients in 2009. The rate of hypertension control increased from 43.6% to 80.4% over that period. By contrast, the overall national control rate increased much less dramatically, from 55.4% to 64.1%. The authors acknowledge the limitations of an observational study and point out that at the beginning of the study, the rate of control was lower than the national level. The growth in size of their patient population may have resulted in the inclusion of more patients who were easier to control.

In an accompanying editorial, Abhinav Goyal and William Bornstein write that despite the enormous amount of research and literature on hypertension, current guidelines “offer little guidance to health systems on how to improve hypertension control in the populations they serve. This deficiency in the guidelines is largely attributable to the lack of science behind health system approaches to blood pressure control.” One significant factor in the success of the Kaiser program is is the reduction of “practice variability by standardizing the approach to care.”

“Although often perceived as undermining individual physician judgment, standardization of care has several advantages when applied across an entire health system, including ease of adoption of best practices across multiple centers, lower likelihood for protocol deviations, lower costs of care, and better outcomes.”

August 20th, 2013

A Pathway to Preventing Research Fraud

In recent years, allegations of misconduct and fraud in the Netherlands and Japan have resulted in retractions of important clinical trials. The Dutch case may well lead to significant revisions in the guidelines for perioperative beta-blockade. The Japanese case involves a Novartis employee who participated in clinical trials without without disclosing his relationship with the company.

When I hear about manipulation and fabrication of data, I am unfortunately not surprised. With the pressure to succeed, some people will act unethically. Concerns about studies are raised only through uncommon observations about something suspicious in the published material. Certainly that approach has to have a low sensitivity for detecting fraud – or error.

The bigger problem is that we have no opportunity to verify most studies because the data are not available to the scientific community. Wouldn’t the situation be different if we had an expectation that people would share their data? We are asked to trust the studies that are published – but shouldn’t we be able to examine the data in detail and verify the findings? If everyone had access to the raw data, wouldn’t that deter fraud and increase the conscientiousness of investigators? Of course, only a small number of people can make sense of raw data. But if the data were available to students throughout the world, to investigators working in the same field, to regulatory agencies interested in the topic – the prospect of verification alone might raise the level of rigor in the work.

The quality of research may vary notably across groups, but that may be hard to tell from published articles. The raw data are likely to reveal much more about a research group’s work. The documentation and organization of the data can provide insight into the care with which the research was conducted.

Maybe it is time to push data sharing, not only to make science more collaborative and efficient but also to provide the opportunity to verify results. Otherwise, what is really to stop some researchers from fabricating their data or manipulating the results – and who can detect an error in coding?

Many details are worth considering, but this might be the pathway to higher-quality, more trustworthy research. What’s your perspective?

 

August 19th, 2013

Selections from Richard Lehman’s Literature Review: August 19th

CardioExchange is pleased to reprint this selection from Dr. Richard Lehman’s weekly journal review blog at BMJ.com. Selected summaries are relevant to our audience, but we encourage members to engage with the entire blog.

JAMA  Intern Med  12/26 Aug 2013  Vol 173

Correlates of Repeat Lipid Testing in Patients With CHD (pg. 1439): Over in the USA, they treat to a target of HDL-cholesterol: over here, we treat to a target of total cholesterol. Let’s call the whole thing off. Both strategies are stupid. Treat to risk, not to target. Once an at-risk person is taking a maximum tolerated dose of statin—as a personal choice—there is no earthly reason ever to measure their lipids again.

JAMA  Vol 310  14 Aug 2013

QRS Duration, Bundle-Branch Block Morphology, and Outcomes Among Older Patients With HF Receiving CRT (pg. 617): I am a fan of cardiac resynchronization (CRT) for heart failure: it helps many people to feel better, and the evidence seems to point to underuse, whereas for implantable cardioverter-defibrillators, the evidence points to overuse. It’s crazy that patients are expected to have both together in nearly all cases. In this large registry study, there was no attempt to distinguish between them, because dual chamber pacing (CRT) was accompanied by defibrillator placement in all 24,169 subjects. It seems to me it should have been accompanied by very careful shared decision making with each patient. But that’s how it was, and this study shows that the benefit of CRT was greatest in those with either left bundle branch block or a QRS duration of 150 ms or greater. As expected.

BMJ  17 Aug 2013  Vol 347

Perceived Job Insecurity as a Risk Factor for Incident CHD: We British GPs may feel harassed, our earnings may be falling, but we know there will always be work for us. But job insecurity is an increasing threat for most people, particularly in the underclass that our present government seems so intent on burdening and disempowering. The poorer you are, the less secure is your employment, so the innumerable authors of this attempted systematic review of the link between perceived job insecurity and coronary heart disease are forced to conclude that the two are essentially inseparable: “The modest association between perceived job insecurity and incident coronary heart disease is partly attributable to poorer socioeconomic circumstances and less favourable risk factor profiles among people with job insecurity.”

Obesity During Pregnancy and Premature Mortality from CV Event in Adult Offspring: And these days, the poorer you are, the more obese you tend to be. But was that true in Scotland sixty years ago? Or even thirty? I find myself making no sense of this record linkage cohort analysis which attempts to link maternal obesity during pregnancy with increased mortality from cardiovascular events in adult offspring in 37 709 Scots with birth records from 1950 to present day. The authors conclude that, “Maternal obesity is associated with an increased risk of premature death in adult offspring. As one in five women in the United Kingdom is obese at antenatal booking, strategies to optimise weight before pregnancy are urgently required.” Hmm. And just what would those strategies be?

Lancet  17 Aug 2013  Vol 317

Cardioprotective and Prognostic Effects of Remote Ischemic Preconditioning in Patients Undergoing CABG (pg. 597): Ischaemic preconditioning is a phenomenon so simple and so weird that it is taking people a long time to come to terms with it. It is as simple as squeezing any part of the body so that its arterial supply is compromised for a short while. Then if you cut off the arterial supply in any other part of the body, you will cause less damage, even if the blockage is permanent. The effect of preconditioning is immediate and lasts for days. In this German trial, they tried it on patients undergoing coronary artery bypass grafting, a procedure which is often accompanied by subclinical cardiac ischaemia, as demonstrated by troponin rises. In the intervention arm, patients under anaesthesia were subjected immediately before CABG to three 10 minute cycles of arm compression to 200mg Hg followed by decompression. Not only were there lower rates of troponin elevation, but “All-cause mortality was assessed over 1•54 (SD 1•22) years and was lower with remote ischaemic preconditioning than without (ratio 0•27, 95% CI 0•08—0•98, p=0•046).” Note the wide confidence intervals, but this is nonetheless pretty amazing.

Reperfusion Therapy for STEMI: Is There Still a Role for Thrombolysis in the Era of Primary PCI? (pg. 624): With you in mind as ever, dear reader, I waded through this cardiology-heavy issue of The Lancet, trying to make sense of special pleading in two industry-funded trials which sought to promote prasugrel and platelet reactivity testing, respectively. Even if I were a cardiologist, this would have been a waste of time. But the clinical review articles are much more worthwhile, and the first one addresses a question which has bugged us all for over a decade: given that timely immediate percutaneous intervention is not always possible for myocardial infarction, what might be the continuing role of immediate thrombolysis as an alternative?  The article goes through the evidence meticulously, and ends up sitting on the fence somewhat, but the message of the conclusion is worth chewing over: “The preferred reperfusion option for patients with STEMI is timely primary PCI, although the recommendation for this approach was based on comparisons with inhospital fibrinolysis alone. Delay to delivery of reperfusion, which predominantly affects primary PCI, leads to an attenuation of benefit compared with fibrinolysis. When the difference in delivery between the two strategies is more than 60 min they seem equal. Furthermore, a pharmacoinvasive strategy of prehospital fibrinolysis plus planned angiography (at 6—24 h in haemodynamically stable patients) and rescue angioplasty for failed fibrinolysis has now been shown to be equivalent (by results of the STREAM trial) or better (by results of the CAPTIM trial) to primary PCI in patients who present early.”

August 19th, 2013

Look Before Leaping to Conclusions About Bush’s Stent

In a recent video interview on TCTMD, interventional cardiologists Ajay Kirtane and Gregg Stone discuss the media reaction to the George W. Bush case and criticize the much-repeated view that Bush’s stent was neither warranted by guidelines nor medically indicated. CardioExchange invited Kirtane to further address the issue. We wondered about the impact of the Bush case on the public perception of PCI, and asked Kirtane if he was concerned whether the publicity about the case might lead to the perception that 1) asymptomatic people should have stress tests, 2) a positive stress test should lead to CT angiogram (CTA), and 3) a positive CTA should lead to PCI, with no discussion of optimal medical therapy (OMT). Here is Dr. Kirtane’s response:

In our discussion on TCTMD, Dr. Stone and I reviewed the various scenarios regarding the Bush case, but rather than jumping to a conclusion that was critical of the patient and physician, we actually tried to explore the various possibilities that could explain the care he received.

What is behind the perception coming out of this case? In my opinion it is because many (press and physicians alike) jumped upon the buzz-worthy “unnecessary” bandwagon rather than a more balanced view, such as one offered by Burt Cohen on his Stent Blog.

Even with the limited details we had, I wonder why the following message wasn’t stressed:

1) Some asymptomatic people CAN have stress tests (at their preference or if they want to vigorously exercise far more than any of the enrolled patients in COURAGE or any other studies). The guidelines are just general guidelines, and individual-based decisions can vary from them.

2) If an asymptomatic person gets a positive stress test, it is absolutely reasonable to order a CTA next (to avoid unnecessary catheterization if the stress is falsely positive or the lesions are not prognostically important). In fact this is EXACTLY one of the scenarios in which I order CTA (typically to avoid invasive cath). That is a VERY IMPORTANT point to mention rather than disparaging a good test.

3) Depending on what the CTA shows, “asymptomatic or minimally symptomatic” patients may or may not get cath/PCI with potential prognostic importance based upon the anatomy. That the CTA is noninvasive ALLOWS AND FACILITATES a discussion of OMT without the patient on the table. How do we know that this case had no discussion of OMT? There are some lesions that even ardent proponents of OMT would agree favor revascularization over OMT alone. As I said on the webcast, because this case was bound to have intense scrutiny almost proves that the anatomy/lesions were serious/dangerous and not trivial.

The plain fact is that, according to colloquial wisdom, it is convenient to think that patients don’t need testing and procedures because it’s easy to paint cardiologists and interventionalists as greedy (or technicians only) and PCI as bankrupting the health care system. That’s why the bias is always to favor doing less and why the press is quick to publish sensationalist (and perhaps even unethical) quotes like, “He is the poster child for the inappropriate use of stenting now” (Boston Herald) or, “This is American medicine at its worst” (USA Today), rather than addressing the far more interesting and disconcerting question of what dangerous disease could have been hiding within the highly active former president while manifesting only minor (or no) symptoms.

This whole area (asymptomatic stable ischemic heart disease) is very tricky and the real truth is that the screening that we do for CAD is frankly not all that good or reliable. That to me is an even bigger story than repeated stories on overuse. What bothers me is that people often discount effective treatments when the real issue is trying to find the right patients in which to use them. The literature has moved well beyond the primary endpoint of COURAGE, and that trial itself can be used to prove both arguments. We also get swept up in the public health/economic debate that is even less personalized and can at times undermine the concept of individualized care. And finally, we have potentially fraudulent cases that only hurt the field further.

 

August 18th, 2013

What Patterns of Change in the Use of Nesiritide Reveal About Hospitals as Learning Organizations

In 2005, safety concerns about nesiritide surfaced in the medical literature, in the media, and in official communiqués from the FDA. To determine how hospitals responded to those concerns and altered their patterns of nesiritide use, my colleagues and I retrospectively analyzed data from the Premier database, including 813,783 hospitalizations for heart failure at 403 hospitals from 2005 to 2010. We applied a growth mixture modeling approach to hospital-level, risk-standardized rates of nesiritide use, to classify hospital groups according to their changing patterns in use of the drug. Our findings, published in JACC: Heart Failure, reveal how hospitals varied in their responses to the new safety information.

Overall, the percentage of hospitalizations for heart failure that involved use of nesiritide declined from 15.4% in 2005 to 1.2% in 2010. An initial sharp drop occurred immediately after safety concerns were publicized, followed by a more gradual decline in subsequent years. That’s not surprising. However, when we analyzed the data at the hospital level, the speed and amplitude of change in nesiritide use varied widely among hospitals. Three distinct groups of hospitals emerged: low-users, fast de-adopters, and slow de-adopters.

The results suggest that common underlying factors within each group of hospitals may explain why they responded so differently. However, we found that these three hospital groups did not differ on traditional hospital characteristics such as size, urban setting, or teaching status. In multivariate regression analysis, none of those standard characteristics was significantly associated with a hospital’s likelihood of being in the slow de-adopter group compared with the other 2 groups.

Those “negative” results were frustrating but not really unexpected. Previous studies have shown that other organizational characteristics — such as team composition (number and type of specialists, inclusion of a pharmacist), internal culture (quality and frequency of communication and collaboration among team members), regulatory context (drug formularies), and availability and use of clinical-decision support systems —have greater impact on medical decision making, evidence-based practice, and hospital performance than do standard hospital categories. However, such organizational characteristics, often called “soft variables,” are not readily available in healthcare databases. Further research using qualitative and mixed methods are therefore required to determine what hospital characteristics actually foster or impede organizational responsiveness.

At this point, some might ask why we analyzed the data at the hospital level rather than physician level. First, hospitalized heart failure patients usually see multiple clinicians because they often have complex disease and multiple comorbidities. Therefore, it is not always possible to identify the prescribing physician. Second, we think the behavior should be attributed to the system structure. For example, it’s important to create an organizational environment where clinicians do not practice in isolated silos but where team building, collaboration, and communication are encouraged. The organization can also provide access to information technology and clinical-decision support systems that help clinicians access timely information, practice evidence-based medicine, and better cope with the uncertainty of accelerating change. This approach is more consistent with the emerging emphasis on systems of care, where the focus shifts from blaming individuals to redesigning how organizations function.

Here are some take-home messages from this study: Changing nature of medical evidence often requires a change in practice. This in turn requires not only access to high-quality, timely information but also a certain degree of “agility” in responding to new evidence. Measuring hospitals’ learning rates, or how quickly and efficiently they respond to new information, could provide important feedback to all stakeholders. It will be crucial to determine what transformations to underlying organizational structure will be associated with greater agility and an improved ability to learn.

As the Greek philosopher Heraclitus once said, “The only constant is change.” In our modern era, the accelerating changes in demographics, economic activity, and technology are challenging our institutions, practices, and beliefs.  In my view, the extent to which we are capable of transforming and reinventing our institutions and the way we practice will be the most critical factor in our journey to a high-quality, high-performance healthcare delivery system.

JOIN THE DISCUSSION

Share your views on the study of nesiritide use patterns by Dr. Partovian and her colleagues. Is your institution agile enough to respond to change rapidly and effectively?

 

August 15th, 2013

Remote Ischemic Preconditioning Beneficial Before CABG

For several decades cardiologists have been intrigued by the concept of ischemic preconditioning. A small body of research has consistently found that brief episodes of ischemia appeared to somehow prepare the body to better handle a major episode of ischemia. Now a new study from Germany holds out the promise that deliberate ischemic preconditioning prior to bypass surgery might prevent ischemic injury caused by the surgery and may even improve long-term survival. But the investigators themselves say that the results need to be confirmed in a larger study.

Matthias Thielman and colleagues randomized 329 patients scheduled for elective CABG surgery at the West-German Heart Center in Essen, Germany to remote ischemic preconditoning or no preconditioning. Patients in the treatment group underwent three cycles of ischemic preconditioning, consisting of inflation of a blood pressure cuff for 5 minutes, followed by a 5-minute period of reperfusion.

Patients in the preconditioning group had significantly less cardiac damage than did controls in the first 3 days following surgery: the area under the curve  for release of cardiac troponin I was 17% lower (CI 3-30%) in the treatment group (266 ng/ml) compared with the control group (321 ng/ml). This short-term difference appeared to result in long-term clinical benefits, yielding significant reductions in mortality and myocardial infarction at 1 year.

“The results of our study are very encouraging that remote ischemic preconditioning not only reduces heart muscle injury but also improves long-term health outcomes for heart bypass patients, and we hope that these benefits will be confirmed in larger prospective studies which are currently taking place” said Gerd Heusch, the senior author of the study, in a press release.

In an accompanying editorial, Nathan Mewton and Michel Ovize write that the “exciting findings… need to be supported by strong experimental evidence and elucidation of the mechanisms underlying the effects of remote conditioning.” The results also need to be tested in large phase 3 studies, they write, such as the ERICCA trial and the RIPHeart-Study which are now underway.