No Increase in Long-term Cardiac Mortality After PCI for Women Compared With Men

Cardiac mortality in the years after undergoing PCI has declined in both men and women, with death now more likely to stem from chronic diseases and cancer. A new study shows that while women do have higher all-cause mortality than men over the long term, those deaths are mostly unrelated to their cardiac disease.

“Prior studies have suggested that the reasons women have higher mortality in the long term after PCI are undertreatment, underprescription of guideline-directed medical therapy, or other hormonal factors that were less well figured out,” said senior study author Rajiv Gulati, MD, PhD (Mayo Clinic, Rochester, MN), in an interview with TCTMD. “I think this study shows that that doesn’t appear to be the cause, and that it really is noncardiac disease and sickness at baseline that’s driving the higher death rate.”

He added that the findings are reassuring from both a PCI standpoint and a secondary prevention standpoint, but do not change the fact that short-term complications and presentation are still vastly different between women and men.

The study was published online March 14, 2018, in Circulation: Cardiovascular Interventions, and was led by Gulati’s colleague Claire E. Raphael, MD, PhD (Mayo Clinic).

Women More Likely to Die of Chronic Disease

Despite multiple studies showing higher rates of long-term mortality after PCI in women compared with men, registry studies attempting to adjust for known baseline characteristics have found the association to be less clear. Some of the registry data have suggested women are as likely or even less likely than men to die after PCI, the researchers write.

For the study, Raphael and colleagues examined cause-specific long-term mortality after PCI in 6,847 women and 16,280 men treated over three time periods: 1991-1997, 1998-2005, and 2006-2012. Across all time periods, all-cause mortality was higher for women than for men, driven by an excess of noncardiac death. A temporal shift toward the cause of death becoming more likely to be noncardiac than cardiac in both sexes also occurred over the study period. Cardiac death decreased by 26% in women and by 17% in men. For the most recent era (2006-2012), cardiac deaths accounted for just 33.8% of all deaths in women and 38% in men.

In adjusted analyses, there was no statistically significant difference in either noncardiac mortality or absolute cardiac mortality at 5 years between women and men.

While women were more likely to die of chronic disease (pulmonary, renal failure, liver failure, neurological, and natural causes), men were more likely to die of cancer. Adjusted analyses for age and baseline comorbidities found no difference in rates of heart failure or chronic disease deaths between the sexes, although the higher rate of cancer for men remained.

Part of the message of this is that we have been doing a great job over the last 20 years, and the improvements have really been reflected in these long-term cardiac outcomes. Rajiv Gulati

Rates of MI and sudden cardiac death at 5 years were similar between the sexes. To TCTMD, Gulati said it is important that there was no evidence of a sex-specific factor influencing cardiac mortality, since some previous studies have speculated that that might be the case.

“It’s really hard to use observational studies to try and understand reasons behind differences between the sexes. The advantage of our database is we do have cause-specific mortality, and I don’t think there are many databases that have that,” he said. “[This study] really addresses the limitations of prior observational studies that had all-cause mortality as an endpoint.”

According to Gulati, improvements in PCI and secondary prevention have allowed noncardiac disease to “declare itself as the more important facet.” Translation: we all have to die of something.

The findings also have implications for clinical trials, he added, since the low rates of cardiac death in the contemporary PCI era may make it difficult to show much of a reduction in long-term mortality for experimental cardiac therapies, necessitating very large enrollment in order to see any difference from baseline.

“Part of the message of this is that we have been doing a great job over the last 20 years, and the improvements have really been reflected in these long-term cardiac outcomes,” Gulati noted.