Does Losartan Lessen Diabetic Cardiac Deaths?
Yes, says LIFE study post hoc analysis
The angiotensin-2 antagonist losartan could be more effective than a beta-blocker in reducing sudden cardiac death among diabetic patients with high blood pressure and left ventricular hypertrophy (LVH), suggest authors of a research letter in the August 23 issue of The Lancet.
The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study published by The Lancet in March 2002 demonstrated a major reduction of all-cause mortality-especially cardiovascular mortality-in patients with diabetes with LVH treated with losartan.
The LIFE diabetes study investigators led by Dr. Lars Lindholm of Umea University in Sweden proposed that losartan might offer better protection than atenolol against sudden cardiac death.
A post hoc analysis of 1,195 participants in the LIFE study showed that 44 patients with diabetes, hypertension, and LVH died of sudden cardiac death. Substantially fewer deaths took place in the losartan group (14 out of 586) than in the atenolol group (30 out of 609). The results showed almost a 50-percent risk reduction in sudden death in losartan-treated patients compared with those treated with atenolol.
The authors, who said the findings of reduced risk in losartan-treated patients were independent of other risk factors for sudden cardiac death, offered a possible explanation for the outcome. They said losartan "has a better antiarrhytmic property than atenolol, which accords with our findings in patients with diabetes with or without atrial fibrillation."
Lindholm said the reduction in sudden cardiac death with losartan was only evident for diabetic patients, but stressed that the results require confirmation.
In an accompanying commentary, Dr. Wilbert S. Aronow of Westchester Medical Center and New York Medical College noted that the new analysis and the previous report "show that losartan is more effective than atenolol in treating hypertensive diabetic patients with left ventricular hypertrophy." However, "a large double-blind randomized trial is necessary to investigate whether losartan is better [than], similar [to], or worse than propranolol, timolol, metoprolol, or carvedilol (all beta-blockers) in reducing sudden cardiac death and coronary events," he says.
Another analysis presented at the European Society of Cardiology convention in Vienna, Austria said losartan also lowered the risk of new-onset atrial fibrillation (AF) among hypertensive patients with LVH. Dr. Kristian Wachtell, author of the posthoc analysis, said the new findings "are particularly important because hypertensive patients are at an increased risk of developing AF and patients with AF have a three- to fivefold increased risk of stroke."
Wachtell's analysis showed that new-onset AF occurred in 179 patients taking the losartan regimen vis-à-vis 252 among those taking the atenolol regimen, representing a 30-percent relative risk reduction (p=0.001).
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