Coronary heart disease (CHD) continues to be a leading cause of morbidity and mortality in the United States, and acute myocardial infarction (AMI) is a common manifestation of CHD, affecting more than 800,000 American adults in 2010. “Concomitant with advances in pre-hospital and hospital treatment, in-hospital survival after AMI has dramatically improved,” says Han-Yang Chen, PhD. “However, many patients are being discharged from the hospital into the community despite being at risk for readmission due to a variety of contributory factors and reasons.”

Dr. Chen adds that excess hospital readmissions are an indicator of potentially poor health care quality or inadequate coordination of post-discharge care. This is costly and represents a significant burden to both patients and the healthcare system.

Since June 2009, CMS began publicly reporting 30-day risk-standardized readmission rates for AMI as one of the major hospital performance measures. The Affordable Care Act has created new payment penalties to reduce readmissions. Hospitals with excess readmissions can lose up to 3% of their Medicare reimbursement by 2015. “As a result, there has been considerable interest to better understand and improve modifiable factors associated with 30-day hospital readmissions, which are increasingly being linked to hospital reimbursement,” says Dr. Chen.


Examining Decade-Long Trends

In a study published in the Journal of the American Heart Association, Dr. Chen and colleagues sought to describe decade-long trends in 30-day rehospitalization rates among patients surviving hospitalization for an AMI from 2001 to 2011. They also described patient characteristics, clinical factors, and treatment practices associated with an increased risk of 30-day rehospitalization among residents of the Worcester, Massachusetts, metropolitan area discharged from three principal medical centers in central Massachusetts after an AMI. Data from the Worcester Heart Attack Study were used in the study.

“Our results show that between 2001 and 2011, nearly one in five patients remained at risk for being rehospitalized within 30 days after discharge for AMI and 36% of all 30-day rehospitalizations occurred during the first week after discharge,” Dr. Chen says. “We observed an encouraging decline that the odds of being rehospitalized during the first 30 days in patients discharged after an AMI in the most recent years (2009 and 2011) was 22% lower than those discharged after an AMI in 2001 and 2003.”


Analyzing the Implications

According to Dr. Chen, the findings suggest that proper arrangement of transitional care and continuing follow-up with patients during the first several days after hospital discharge may help reduce hospital readmission rates within 30 days among these patients. “Our observation that there was a decline in the proportion of patients who were readmitted during the first week after hospital discharge over the decade studied may suggest that efforts at reducing hospital readmissions are paying dividends in reducing short-term hospital readmissions,” says Dr. Chen.

The study notes that 38% of all 30-day rehospitalizations were not related to cardiovascular disease (CVD). “As the prevalence of comorbid conditions and aging of Americans increase over time, 30-day rehospitalizations after AMI due to non-CVD causes require further attention,” Dr. Chen says. Recent research has also suggested that patients discharged from the hospital may be vulnerable to “post-hospitalization syndrome,” which puts them at risk for rehospitalization for conditions unrelated to their initial hospitalization.


Looking Ahead

Dr. Chen says that future studies are warranted to continue monitoring changes in 30-day rehospitalization rates after the implementation of financial penalties to hospitals due to excess readmissions since 2012. Future studies examining the post-discharge transitions of care in higher-risk patients—including those with multiple comorbid conditions and hospital clinical complications—are needed to achieve greater declines in 30-day rehospitalizations in this patient population.


Chen HY, Tisminetzky M, Lapane KL, et al. Decade-long trends in 30-day rehospitalization rates after acute myocardial infarction. J Am Heart Assoc. 2015 Nov 3 [Epub ahead of print]. Available at:

Dunlay SM, Weston SA, Killian JM, Bell MR, Jaffe AS, Roger VL. Thirty-day rehospitalizations after acute myocardial infarction: a cohort study. Ann Intern Med. 2012;157:11–18.

Krumholz HM, Lin Z, Drye EE, Han LF, Rapp MT, Mattera JA, Normand SL. An administrative claims measure suitable for profiling hospital performance based on 30-day all-cause readmission rates among patients with acute myocardial infarction. Circ Cardiovasc Qual Outcomes. 2011;4:243–252.