February 10th, 2014
Selections from Richard Lehman’s Literature Review: February 10th
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.
Lancet 8 Feb 2014 Vol 383 and NEJM 6 Feb 2014 Vol 370
Cobalt Intoxication Diagnosed with the Help of Dr. House (Lancet, pg. 574) and Missing Elements of the History (NEJM, pg. 559): At the opposite end of the medical spectrum from being a British GP is the acerbic American Dr Greg House (aka actor Hugh Laurie, son of an Oxford GP), whose diagnostic acumen makes up for his complete disregard for conventional ethics. A terrible role model, but he may have actually saved a life—for real. In one episode of House, the eventual diagnosis is cobalt poisoning, which causes heart failure. Ever heard of it? There are two reports of cobalt induced heart failure in this week’s journals, and in the Lancet case, it was a House watcher who made the connection between a dodgy hip replacement and the failing heart. Here in the NEJM, the diagnosis was only made after the patient had a heart transplant. There have probably already been thousands of cobalt related deaths in older patients with progressive heart failure of uncertain cause. From now on, cardiologists need to think cobalt in every heart failure patient with a metal hip prosthesis.
JAMA Intern Med Feb 2014
Transfer Rates From Nonprocedure Hospitals After Initial Admission and Outcomes Among Elderly Patients With Acute MI (pg. 213): Once again, the monthly journal floods us with an embarrassment of riches. I’m picking out this US study of transfer rates for myocardial infarct patients from non-PCI-providing hospitals to PCI-providers because (a) it shows wide and unaccountable variation in practice (b) it shows very little difference in outcomes according to rates of transfer and (c) I was at Yale when it was being done. It’s a typically high quality product from the Center for Outcomes Research and Evaluation. Conflict of interest statement: I love these guys and the work they do.
CABG vs. PCI and Long-term Mortality and Morbidity in Multivessel Disease (pg. 223):
“The time has come,” the Walrus said,
“To talk of many things:
Of shoes—and ships—and sealing-wax—
Of cabbages—and kings—
And why the sea is boiling hot—
And whether pigs have wings.”
There was a time when CABG was king: it was the most commonly performed major operation in the developed world. Then along came stents, and percutaneous coronary intervention developed wings. Boiling hot rows have ensued between surgeons and interventional cardiologists about how to interpret the sea of evidence. But the authors of this systematic review stamp their sealing wax down firmly in favour of CABG for 3+ vessel disease: “In patients with multivessel coronary disease, compared with PCI, CABG leads to an unequivocal reduction in long-term mortality and myocardial infarctions and to reductions in repeat revascularizations, regardless of whether patients are diabetic or not.”
PCI Outcomes in Patients With Stable Obstructive Coronary Artery Disease and MI (pg. 232): But does either of these cardiological pigs really have wings? The next systematic review looks at all randomized clinical trials of PCI and medical treatment vs MT alone for stable coronary artery disease in which stents and statins were used in more than 50% of patients. Their conclusion supports COURAGE: “In patients with stable CAD and objectively documented myocardial ischemia, PCI with MT was not associated with a reduction in death, nonfatal MI, unplanned revascularization, or angina compared with MT alone.”
JAMA 5 Feb 2014 Vol 311
Effects of Immediate BP Reduction on Death and Major Disability in Patients With Acute Ischemic Stroke (pg. 479): Most of this week’s JAMA is about high blood pressure. As we all know, long term BP and stroke risk show a nice linear relationship: and most of us in medicine, myself included, find comfort in simple things. It follows that a lot of patients who present with stroke also present with high blood pressure, and the temptation is to get it down as fast as possible. This idea was tested in 2038 patients admitted to Chinese hospitals: “Among patients with acute ischemic stroke, blood pressure reduction with antihypertensive medications, compared with the absence of hypertensive medication, did not reduce the likelihood of death and major disability at 14 days or hospital discharge.” BP lowering is a long-term strategy to prevent a second event, not an immediate necessity.
BP Trajectories in Early Adulthood and Subclinical Atherosclerosis in Middle Age (pg. 490): Blood pressure is an actual thing, but individual blood pressure measurements are a surrogate for what happens over decades within the circulation. Coronary artery calcium is also something real, but is just a distant surrogate for the thing that matters, which is unstable atheroma in the blood vessels supplying the myocardium. Marry up the two and you have a happy pair of surrogate parents: but what for? The trouble with blood pressure research is that it needs a decade or more to provide real knowledge about outcomes. This study identifies five trajectories of BP in younger adults, and links the higher ones with “subclinical atherosclerosis,” meaning a higher coronary calcium score. We get the drift: but how does this help us manage individual, perfectly asymptomatic, real people?