July 7th, 2014

Selections from Richard Lehman’s Literature Review: July 7th

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.

NEJM 3 July 2014 Vol 371

Loss-of-Function Mutations in APOC3 and Ischemic Vascular Disease, Triglycerides, and Coronary Disease (pg. 22, 32): My heart sank last week when two papers appeared on the NEJM website with the titles Loss-of-Function Mutations in APOC3, Triglycerides, and Coronary Disease, and Loss-of-Function Mutations in APOC3 and Risk of Ischemic Vascular Disease. I resolved to ignore them. However, Harlan Krumholz ‘s comments on them really have to be read: “This research”, he said, “has absolutely no implications for clinical practice. It might one day be seen as a pivotal study that led to the development of remarkable drugs, but that is far away. I hope people don’t read it and think that it has relevance to their current decisions about treatment.”

JAMA Intern Med July 2014

Effect of Patients’ Risks and Preferences on Health Gains With Plasma Glucose Level Lowering in Type 2 Diabetes Mellitus: Four years ago, John Yudkin drew my attention to a study that had just appeared in the Archives of Internal Medicine, illustrating a new and radically patient centred kind of modelling for “utility versus disultility” in long term treatment. It appeared under the banner of “LESS IS MORE” and bore the title: “Variation in the Net Benefit of Aggressive Cardiovascular Risk Factor Control Across the US Population of Patients With Diabetes Mellitus.” It should have shaken the world but, as so often in this field, it was politely ignored because it ran counter to the standard model of practice. John had heard that the Michigan authors had another paper up their sleeve, dealing with the individual utilities or disutilities of varying degrees of glucose control in the same population. We grew so eager to see this published, that John went over to recruit Harlan K at Yale to join forces in urging Rod Hayward to complete work on it. I joined the trip and my life was changed, but the study has only now been published.

Everybody should read it. “Treating patients with HbA1c levels less than 9% should be individualized on the basis of estimates of benefit weighed against the patient’s views of the burdens of treatment.” Do you dare to have this discussion with your patients with longstanding type 2 diabetes mellitus? Or with any other patient you have “put on” long term treatment? “We estimate that the expected gain in QALYs for a 1-point change in HbA1c level in a 75-year-old is 0.06 years (22 days), even with the favorable assumption that glycemic control’s cardiovascular benefit extends to the elderly.” Now go back to their original paper and think hypertension.

The BMJ 5 July 2014 Vol 349

Revascularization vs. Medical Treatment in Patients with Stable CAD: Network meta-analyses are a mixed blessing. Experts argue that by using a bayesian random effects Poisson regression model, you can preserve randomised treatment comparisons within trials. But that begs the question of how you can achieve dependable comparisons between trials, robust enough to guide clinical practice. Unfortunately I was born with loss of function variants on my STATS-WONK alleles and cannot work that out. This network meta-analysis would have us believe that the era of COURAGE has come to an end: thanks to better drug eluting stents and techniques for coronary artery bypass surgery, people with stable coronary artery disease will now experience fewer deaths and myocardial infarctions if they have early invasive treatment. But I couldn’t dig out the figures that would allow me to share any decisions confidently with actual patients. I fear that this meta-analysis, which is very hard to confirm or contest, will simply be used as a pretext for interventionists to return en masse to their bad old habits.



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