Beta blockers, such as atenolol, are associated with a 50 percent reduction in sudden cardiac death in high-risk patients. These agents are believed to be more effective than angiotensin-converting enzyme (ACE) inhibitors in patients with hypertension and left ventricular hypertrophy. Nevertheless, in a large multinational trial, cardiovascular mortality was significantly reduced in patients with diabetes and left ventricular hypertrophy during treatment with losartan. Lindholm and colleagues postulated that losartan might be more effective than atenolol in preventing sudden cardiac death in diabetic patients.
The authors analyzed data from the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study, focusing on participants with diabetes. The 1,195 participants had a mean age of 67 years and average blood pressure of 177/96 mm Hg. Fifty-three percent were women. Patients were randomly assigned to treatment with losartan or atenolol and followed for an average of 4.7 years. Significantly fewer cardiovascular deaths occurred in the patients receiving losartan (38, equivalent to 13.6 per 1,000 patient years of follow-up) than in those receiving atenolol (61, equivalent to 21.8 per 1,000 patient years). The reduction was most marked in sudden cardiac deaths, in which the rate per 1,000 patient years was 5.0 for the losartan group compared with 10.7 for the atenolol group (see accompanying table). Serum potassium levels were similar in the two groups. Adjustments for left ventricular hypertrophy did not explain the differences in sudden cardiac death between the groups. Ten percent of the 191 patients with diabetes and atrial fibrillation died during the follow-up period, compared with only 2 percent of the 1,004 patients with diabetes but without atrial fibrillation. Patients with atrial fibrillation treated with losartan had a lower rate of sudden cardiac death (6 percent compared to 2 percent), but the difference could not be explained by a sudden discontinuation of atenolol.
The authors conclude that patients with diabetes who were treated with losartan showed a 50 percent reduction in sudden cardiac death compared with patients treated with atenolol. This effect was not noted in participants who did not have diabetes, in which equal numbers of sudden cardiac deaths occurred in both treatment groups. They propose that the advantage for losartan could be caused by better anti-arrhythmic properties, especially in reducing the risks of atrial fibrillation. However, other effects, especially modulation of sympathetic nerve activity, are probable. The authors call for further studies to investigate the unique needs of patients with diabetes who are at risk of cardiac death.
editor’s note: The role of the family physician following myocardial infarction used to be limited to aggressive support of patients undertaking preventive measures, such as smoking cessation, weight control, and exercise. Growing evidence for several therapeutic interventions allows physicians to do so much more. This study points to a future when we will be able to tailor a therapeutic regimen specific to the needs of individual patients. This research comes at an opportune time as the “baby boomers” in America reach a higher risk of cardiac disease, exacerbated by the epidemic of obesity and diabetes. Combining our traditional emphasis on prevention with more effective active treatments should enable us to offer patients at high risk of cardiac disease (or with established cardiac disease) much better prognosis. We must not, however, lose the person in the therapy. Most patients with significant heart disease (and their family members) are frightened; up to 47 percent of them develop significant depression.1 These patients deserve a truly comprehensive approach from a skilled family physician.—A.D.W.