Jan. 9, 2007 -- For heart attackheart attack survivors, it really is important to follow doctor's orders: A Canadian study shows you may be less likely to die if you continue taking the drug he prescribes.
The study of 31,455 heart attack survivors found 24% of the patients worst about continuing their medicine died over the course of the study, compared to 16% of those best at taking their medication.
The patients, who were 66 and older, were followed for 2.4 years, on average, after their heart attack.
Researchers, including the University of Toronto's David Alter, MD, PhD, FRCPC, studied how long the patients continued refilling their prescriptions. Their report appears in The Journal of the American Medical Association.
About the Drugs
All of the patients survived at least one year and three months after their heart attack.
Most took their drugs faithfully for the first year. But adherence fell later on.
Of the Canadian patients, 57% filled a prescription for a statin, 77% filled a prescription for a beta-blocker, and 30% for a calcium-channel blocker within three months after hospital discharge for their heart attack. (Some took more than one type of drug.)
Among those with statin prescriptions, 13% had stopped taking their statins by the time the study ended. A fifth of those with beta-blocker prescriptions quit taking their beta-blockers. A third of those with calcium-channel blocker prescriptions had stopped taking those drugs.
It's not clear why the patients stopped taking the drugs, which were free under the Canadian health care system.
Better Adherence, Longer Lives
About 14,300 patients stuck with their statin prescriptions for at least 80% of the days studied. Those patients had the lowest death rate -- 16% -- during the study.
An additional 2,407 patients followed their prescriptions for 40% to 79% of the days studied. They had the second-lowest death rate: 20%.
The highest death rate occurred in the patients with the lowest drug adherence.
Those patients took their drugs for less than 40% of the days studied. Nearly a quarter of them -- 24% -- died during the course of the study.
Survival Rate by Drug
People who kept taking their statin drugs had the best survival rates, followed by those taking beta-blockers.
Calcium-channel blockers weren't associated with longer (or shorter) lives.
But they did adjust for many factors, including the patients' age and other health problems.
Moral of the story? It's important to follow prescriptions carefully. And if you have concerns about a drug you're taking, talk with your doctor before quitting the drug or making changes.