Clot-buster's cost-effectiveness questioned.

Clot-buster's cost-effectiveness questioned

Two patients share a hospital room for a couple of days after suffering a heart attack. Both do well, thanks largely to treatment with clot-dissolving drugs within the first few hours after their initial attacks. One received recombinant tissue plasminogen activator (rt-PA) and the other received streptokinase.

Tests reveal that in both patients, coronary arteries are again supplying blood and oxygen to the heart, and the all-important measures of left ventricular function are close to normal again. Indeed, according to a study in the March 30 NEW ENGLAND JOURNAL OF MEDICINE, the only apparent difference between the two patients' recoveries may be in their hospital bills. A course of streptokinase costs about $200, while rt-PA goes for more than $2,200.

The multicenter study, performed in Auckland, New Zealand, adds fuel to a growing controversy over the relative value of different clot-dissolving therapies for heart attack patients. It appears to contradict previous research that showed benefits of rt-PA over the cheaper streptokinase. "Streptockinase and rt-PA, when given within three hours of the onset of a first myocardial infarction, have similar effects on the preservation of left ventricular function" and show no significant differences in other measures of cardiac recovery, the researchers conclude in their study off 270 patients.

But the report generates as many questions as answers, researchers say. What, for instance, is the ideal indicator of a drug's effectiveness? Of three studies directly comparing rt-PA and streptokinase, including this latest report, each used a slightly different measure of cardiac recovery taken at somewhat different intervals. and each came to a slightly different conclusion, although differences in outcome between the two groups have generally been subtle.

The real indicator of drug superiority--mortality reduction--requires larger and longer-term clinical trials than those performed to date. Researchers hope one such trial, now underway in Italy, will provide useful data in 1990.

"If one agent is superior to another in terms of benefit to the patient, then cost is less of an issue," writes the New Zealand research team, led by Harvey D. White of the Green Lane Hospital. "But if two agents are similar, cost may be a major consideration." Given the available data, they conclude, "the lower cost of streptokinase is an important factor in its favor."