While coronary artery disease (CAD) patients with both ischemia and angina proved to have higher risks for mortality, 58.2 percent of patients without symptoms died of cardiovascular- or MI-related causes, according to a study published online Aug. 11 in JAMA: Internal Medicine.
Philippe Gabriel Steg, MD, of the Assistance Publique–Hôpitaux de Paris, and colleagues reviewing data submitted to the Prospective Observational Longitudinal Registry of Patients With Stable Coronary Artery Disease (CLARIFY) project found that hazard ratios for ischemia, angina or both showed increasing risk of mortality for patients with these compounding conditions on top of CAD.
Among these patients, Steg et al noted, the highest risk of cardiovascular-related death occurred in patients with both ischemia and angina (hazard ratio 1.75). This accounted for 17.3 percent of deaths in the analysis population. Patients with angina represented 12.2 percent of cardiovascular deaths (hazard ratio 1.45) and 12.4 percent occurred in patients with ischemic symptoms (hazard ratio 0.9).
Of the total patients entered into this database, this reflects an overlapping set of percentages. Angina symptoms plagued 20 percent of all CAD patients enrolled in the registry and 25.8 percent of patients had evidence of MI.
But what of the remaining patients?
This group represented 65.1 percent of all patients and 58.4 percent of cardiovascular-related deaths occurred in patients who did not present with ischemia or angina. This same group experienced 70.4 percent of all events that occurred in the course of the study.
While the combination of angina and ischemia negatively impacted patients in the study, Steg et al offered possibilities only as to why neither of these two symptomologies were fully indicative of outcome. Among the possible reasons given, they cited the size of the nonangina or ischemia cohort, the presence of potential undetected angina or ischemia (from lack of adequate testing), or potential underreporting.
They noted, however, that they found an increased risk in patients with angina but no evidence of inducible ischemia over patients with asymptomatic ischemia, which was at odds with earlier studies. They suggested that this may have to do with angina patients being unable to complete exercise tests.
Steg et al wrote that their findings highlighted “the importance of implementing optimal medical therapy and preventative measures regardless of symptoms or ischemia” and also showed the importance of adequate testing to ensure the best prognostic effect.