For acute MI patients, readmissions for unstable angina or unplanned revascularization worsen outcomes

Within one year of having an acute MI, patients who were rehospitalized for unplanned coronary revascularization or unstable angina had statistically and clinically significant decreases in disease-specific and global health status measures, according to a registry analysis.

Lead researcher Supriya Shore, MD, MSCS, of Atlanta's Emory University School of Medicine, and colleagues published their results online Oct. 25 in Circulation: Cardiovascular Quality and Outcomes. Eli Lilly funded the study through a research grant.

“Our observations suggest that patient health status is clinically important as a marker of population-level cardiovascular health,” the researchers wrote.

The researchers analyzed data on 3,283 patients who enrolled in the prospective, multicenter, observational TRIUMPH registry between April 11, 2005, and Dec. 31, 2008, at 24 U.S. medical centers. All patients were at least 18 years old and were diagnosed with acute MI within 24 hours of hospital admission.

For a propensity-matched cohort, the researchers also identified a group of patients who did not have unplanned coronary revascularization or unstable angina but were similar to the patients enrolled in the registry. The propensity-matched cohort for unplanned unstable angina rehospitalization included 2,433 patients, while the propensity-matched cohort for unplanned coronary revascularization rehospitalization included 2,410 patients.

The mean age was 59 years old, while 33 percent of patients were women and 70 percent were white. In addition, 66 percent of patients had hypertension, 29 percent had diabetes, 20 percent had previous MI, 19 percent had previous PCI and 11 percent had previous CABG.

During the first year after suffering an acute MI, the rehospitalization rates for unplanned angina and unplanned revascularization were 4.3 percent and 4.7 percent, respectively. Further, the one-year Seattle Angina Questionnaire summary scores and EuroQol-5D Visual Analog Scale scores were worse among patients who were rehospitalized for unplanned angina or revascularization.

The study had a few limitations, according to the researchers, including that they only included rehospitalizations that were available for adjudication. They also relied on self-reported rehospitalizations. In addition, the observational design of the study meant the researchers could not prove a causal association between rehospitalizations and patient health status.

“These findings highlight the interaction between patient health status and repeat rehospitalizations for [ustable angina] and unplanned coronary revascularizations beyond their economic impact to society,” the researchers wrote. “Although our findings may justify the use of rehospitalizations as an end point in clinical trials, they also suggest a need for future research to better determine whether close monitoring of patients’ health status might identify those at risk for readmission, who therefore could be targeted for more aggressive treatment strategies to prevent rehospitalizations while also preserving or improving health status.”