April 2nd, 2013
Selections from Richard Lehman’s Literature Review: April 2nd
CardioExchange is pleased to reprint selections 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 27 Mar 2013 Vol 309
Effect of Disodium EDTA Chelation Regimen on CV Events in Patients With Previous MI (pg. 1241): Have you ever heard of someone who’s recently had a heart attack going off and having 40 infusions of disodium ethylenediaminetetraacetic acid, ascorbate, B vitamins, electrolytes, procaine and heparin? No, I hadn’t either, until I went to give a talk to some cardiac rehabilitation patients about 12 years ago.
I said my little piece about all the lovely medical progress being made, and then took questions. They were all about chelation therapy, and I was reduced to desperately scanning the large room for means of escape while saying that I looked forward to reading the results of large randomized trials of this improbable mumbo-jumbo – though I might not have used those precise words. And here, at last, it is! A large, well-conducted trial (TACT) of chelation versus intravenous placebo in 1708 survivors of myocardial infarction. The trend to benefit is consistent and adds up to a statistically significant reduction in adverse cardiovascular events, driven largely by a reduction in the perceived need for revascularization. But this cannot be true, argues Steve Nissen in a commentary. They must have cheated. Harlan Krumholz has fun taking the opposite view in a Forbes Weekly piece: “This study has opened my mind to the possibility that there may be something more to this therapy than I originally thought. And given what I thought about it before, I can hardly believe I am writing that.”
NEJM 28 Mar 2013 Vol 368
Effects of Off-Pump and On-Pump CABG at 1 Year (pg. 1179): Did I imagine it, or did I really see a tweet from a cardiac surgeon describing off-pump coronary bypass grafting as “like making love while standing up in a canoe: it can be done, but why would you want to?” Well, there’s the showing off of technical skill – no, wait, I am getting mixed up here – cardiac surgeons are not like that; it must be to achieve better neurocognitive outcomes for patients. Forget the canoe: let’s look at what happens when these surgeons stand on the terra firma of their operating rooms and perform CABG, using a cardiac bypass pump or not according to randomization schedule. The first large trial in this week’s NEJM randomized 4752 patients, and conclusion is “At 1 year after CABG, there was no significant difference between off-pump and on-pump CABG with respect to the primary composite outcome, the rate of repeat coronary revascularization, quality of life, or neurocognitive function.”
Off-Pump vs. On-Pump CABG in Elderly Patients (pg. 1189): The second trial looked at outcomes in 2539 Germans aged 75 or over, where cognitive effects might be expected to show up more clearly. But oddly enough, they were not looked for. The primary end-points that were measured showed “no significant difference between on-pump and off-pump CABG with regard to the composite outcome of death, stroke, myocardial infarction, repeat revascularization, or new renal-replacement therapy within 30 days and within 12 months after surgery.” So that’s it for off-pump CABG. It’s just showing off. Oops darling, splash!
Treatment of Anemia with Darbepoetin Alfa in Systolic HF (pg. 1210): Anaemia is a very common accompaniment to heart failure, and each decrement of haemoglobin is associated with worse survival, so it would seem logical to try and do something about it. But this randomized trial shows that using darpoetin alfa to achieve a haemoglobin of 13 in patients with systolic HF does not reduce death or hospitalization for HF. It does not even improve symptoms.
Lancet 30 Mar 2013 Vol 381
Use of Clopidogrel With or Without Aspirin in Patients Taking Oral Anticoagulant Therapy and Undergoing PCI (pg. 1107): Patients who are taking oral anticoagulants and who need to have percutaneous coronary intervention are, it seems, often loaded up with both aspirin and clopidogrel prior to the procedure, and not surprisingly they have a high incidence of bleeding. This trial from Belgium and the Netherlands tried the effect of omitting the aspirin and just using clopidogrel in a randomised comparison with standard triple therapy. “Use of clopiogrel (sic) without aspirin was associated with a significant reduction in bleeding complications and no increase in the rate of thrombotic events.”