Purpose:
Patients who present with concurrent heart failure (HF) and acute coronary syndrome (ACS) have an increased risk of mortality, but changes in clinical practice have improved clinical outcomes. We sought to examine recent trends in concurrent HF and ACS hospitalizations in the United States (US) through review of published literature.
Methods:
We searched the Medline and PubMed databases for studies published after January 1, 2000 reporting the hospitalizations for HF with concurrent acute coronary syndromes. We included studies performed in the US or with at least 25% US participants, that reported the proportion with concurrent HF and ACS, and used a clinical definition of HF (e.g. Killip Class II or III, NYHA Class, or Framingham Criteria). Studies were reviewed by and data was extracted using a standardized form. We extracted study and patient characteristics, definition of HF, and rates of concurrent HF and ACS hospitalizations. We categorized included studies by ACS type: (1) non-specific myocardial infarction (MI) or ACS, (2) non-ST elevation (NSTE) MI or NSTE-ACS, or (3) ST elevation (STE) MI. We descriptively examined recent trends in hospitalizations for concurrent HF and ACS over time; rates reported for multiple time periods or ACS types were considered separately.
Results:
We identified 23 observational studies, systematic reviews, and randomized clinical trials. Of these, we excluded 13 due to non-US populations, use of non-clinical definitions of HF (i.e., diagnosis codes), or not reporting rates of concurrent HF and ACS. Of the 10 included studies, 7 reported concurrent HF with non-specific MI or ACS from 1975 through 2005 across multiple registries and literature reviews. Rates ranged from 12.5% to 48.0% with no clear time-related trends. We identified 3 studies reporting concurrent HF with NSTEMI or NSTE-ACS from pooled analysis or the Global Registry of Acute Coronary Events (GRACE) registry from 1994 to 2008. Reported rates ranged from 8.2%-15.7% for studies starting in the 1990s with one study reporting and 6.1% in 2005. We identified 4 studies reporting concurrent HF with STEMI, including a pooled analysis, the GRACE registry, and a clinical trial. Rates of concurrent HF with STEMI appeared to decrease over time from 32.5% in 1990 to 1998, 15.6%-19.5% from 1999 to 2001, and 2.6%-11.0% in 2005.
Conclusion:
Our literature review found that there may be a decrease in concurrent HF and STEMI hospitalizations in recent decades, but no apparent trends with other types of ACS. This may be related to emphasis on early revascularization strategies, improved primary prevention, and/or earlier time to presentation due to increasing public awareness.. However, there was a dearth of data reporting concurrent HF and ACS hospitalization within the last decade. Further research is needed to understand the impact of multiple changes in clinical practice on secular trends.
Toward a Typology of Critical Nonprofit Studies: A Literature Review
