Risk of cardiac death after PCI diminishes after 30 days

Cardiac mortality risks fell at the one-year mark for patients who underwent primary PCI following acute STEMI. A study published in the Nov. 18 issue of the Journal of the American College of Cardiology found that while 30-day risks for cardiac death were elevated, the longer a patient survived, the more risk moved away from cardiac toward noncardiac death.

Frants Pedersen, MD, PhD, of the cardiology department at the University of Copenhagen in Denmark, and colleagues examined outcomes for 2,804 consecutive STEMI patients who underwent PCI between 1998 and 2008. The data were collected using Danish patient registries and matched with Danish civil personal registration numbers. Patients were followed for a median of 4.7 years.

They found that over the follow-up period, mortality rates shifted between a stronger association toward cardiac death at 30 days to noncardiac-related cause of death at one year or five years. Patients experienced a 7.9 percent mortality rate for any cause and 7.3 percent for cardiac mortality at 30 days. One-year all-cause mortality rates were 11.4 percent, while the cardiac mortality rate was 8.4 percent by that period. Five-year mortality rates were 23.3 percent and 13.8 percent for all-cause and cardiac death, respectively.

At 30 days, the most frequent causes of death were cardiogenic shock (19.5 percent), anoxic brain damage (3.1 percent) and malignant arrhythmia (1.7 percent). Meanwhile, after the first 30 days, reinfarction (6.3 percent) and cerebrovascular disease (5.6 percent) became more common. The found, however, that after one year, death was most frequently attributable to cancer and malignancies (17.3 percent) followed by sudden cardiac death (15.5 percent), pneumonia and acute respiratory distress (9.1 percent) or congestive heart failure (4 percent).

Risk of early death where thrombolysis in MI flow was slow was 2.5 times higher, they noted. Other strong prognosticators of outcome included age, diabetes, history of heart failure and large culprit vessel diameter.

They noted that their findings suggested, much like those of prior studies, that mortality can be affected by changes to medical regimens, as early as the timing of the initial PCI itself. Pedersen et al wrote, “Our findings also stress the importance of careful interpretation of interventional studies that focus on the effect of different treatment strategies on long-term clinical outcomes.”

In an editorial, Mark A. Hlatky, MD, of Stanford University School of Medicine in California, wrote among the important takeaways from Pedersen et al is that “we cannot rest on our laurels after successful treatment of an acute MI. We need to recognize factors, both cardiac and noncardiac, that pose the greatest risk to patients who survive an MI and initiate the therapies and behavior changes that will reduce the risk of late mortality.”