Preventing CHF with HTN Treatment in SHEP Patients
ABSTRACT & COMMENTARY
Synopsis: In older patients who have isolated systolic hypertension, use of chlorthalidone prevents heart failure. An 80% risk reduction was seen in patients who have prior evidence of myocardial infarction on their EKG.
Source: Kostis JB, et al. JAMA 1997;278:212-216.
The systolic hypertension in the elderly program (SHEP) previously demonstrated that elderly patients over the age of 60 with isolated systolic hypertension (ISH) treated with their unique (older) version of stepped-care treatment (low-dose chlorthalidone) reduced the incidence of total stroke by 36% and cardiovascular events by 32%. Now, the investigators have turned specifically to the percent development of heart failure.
By looking at the data from this placebo-controlled, double-blind, randomized, multicenter clinical trial, they teased out a pre-existing condition of an EKG abnormality as well as the development of heart failure in all patients. The SHEP cooperative research group was able to statistically analyze the data and develop relative risks for the development of heart failure in patients with either normal EKGs or abnormal EKGs. They looked at fatal and nonfatal heart failure, hospitalized or not, as well as cardiac mortality. The 4.5-year findings show the development of 55 cases of fatal or nonfatal heart failure in the 2365 patients randomized to active therapy compared to 105 of the 2371 patients randomized to placebo. This gives a relative risk of about 0.5.
In patients who had electrocardiographic evidence of myocardial infarction prior to randomization, the numbers dramatically shot up, with a relative risk of 0.19 (i.e., an 80% risk reduction was observed). Looking back at the entry criteria, they found that older patients, men, and those with high systolic blood pressures or a history of ECG evidence of MI baseline were predictive of developing heart failure.
COMMENT BY LEN SCARPINATO, DO
Congestive heart failure still represents a significant health problem, although, in the last 15 years, primary care physicians clearly have had much more added to our armamentarium to fight this problem. Our cardiology colleagues’ invasive procedures are allowing patients to develop these heart failure syndromes later in life. Yet, there are still one million hospitalizations in the United States annually due to heart failure. Most of us are conversant with the difference between diastolic and systolic dysfunction which has ramifications for treatment, but these data cannot be ascertained from the SHEP trial.
What we can analyze from the SHEP trial is that the diuretic-based stepped-care therapy is significantly better than placebo. What a marked difference from what people were talking about five or 10 years ago when we used to ignore isolated systolic hypertension. Now we know from SHEP that stroke can be decreased by treatment as well as the development of heart failure.
I, for one, am going to look for isolated systolic hypertension and talk to my elderly patients about reducing their blood pressure With a relatively non-expensive drug, chlorthalidone, I can reduce their rate of stroke and heart failure. It would be wonderful if we knew whether the same effect could be seen with agents that were easier to use. In their study, they used atenolol for those patients who failed chlorthalidone. These two are older drugs compared to what we’ve all become used to using; however, since most of these patients are on fixed incomes, I think it’s not unreasonable that we would attempt using these drugs.