Percutaneous Coronary Intervention in Older Patients With ST-Segment Elevation Myocardial Infarction and Cardiogenic Shock

Abstract

Background: Older adults ≥75 years of age carry an increased risk of mortality after ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock.

Objectives: The purpose of this study was to examine the use of percutaneous coronary intervention (PCI) in older adults with STEMI and shock and its influence on in-hospital mortality.

Methods: We used a large publicly available all-payer inpatient health care database sponsored by the Agency for Healthcare Research and Quality between 1999 and 2013. The primary outcome was in-hospital mortality. The influence of PCI on in-hospital mortality was assessed by quintiles of propensity score (PS).

Results: Of the 317,728 encounters with STEMI and shock in the United States, 111,901 (35%) were adults age ≥75 years. Of these, 53% were women and 83% were Caucasians. The median number of chronic conditions was 8 (interquartile range: 6 to 10). The diagnosis of STEMI and cardiogenic shock in older patients decreased significantly over time (proportion of older adults with STEMI and shock: 1999: 42% vs. 2013: 29%). Concomitantly, the rate of PCI utilization in older adults increased (1999: 27% vs. 2013: 56%, p < 0.001), with declining in-hospital mortality rates (1999: 64% vs. 2013: 46%; p < 0.001). Utilizing PS matching methods, PCI was associated with a lower risk of in-hospital mortality across quintiles of propensity score (Mantel-Haenszel odds ratio: 0.48; 95% confidence interval [CI]: 0.45 to 0.51). This reduction in hospital mortality risk was seen across the 4 different U.S. census bureau regions (adjusted odds ratio: Northeast: 0.41; 95% CI: 0.36 to 0.47; Midwest: 0.49; 95% CI: 0.42 to 0.57; South: 0.51; 95% CI: 0.46 to 0.56; West: 0.46; 95% CI: 0.41 to 0.53).

Conclusions: This large and contemporary analysis shows that utilization of PCI in older adults with STEMI and cardiogenic shock is increasing and paralleled by a substantial reduction in mortality. Although clinical judgment is critical, older adults should not be excluded from early revascularization based on age in the absence of absolute contraindications.

Keywords: ST-segment elevation myocardial infarction; cardiogenic shock; mortality; older adults; percutaneous coronary intervention.

Figure 1. Overlap plot for propensity score.

Overlap plot for the estimated density of the propensity scores among older adults presenting with ST-elevation myocardial infarction (STEMI) and cardiogenic shock treated with versus without percutaneous coronary intervention (PCI) in (A) raw data (B) weighted data.

Figure 2. Older adults with ST-elevation myocardial infarct (STEMI) and cardiogenic shock by regions of the United States over the study period (1999–2013).

Note that the percent older adults (y-axis) is calculated as the number of admissions for older patients divided by the total number of admissions for STEMI and cardiogenic shock by region of the U.S. overtime.

Figure 3. Adjusted probability of death in older patients with ST-elevation myocardial infarction (STEMI) and cardiogenic shock by treatment with percutaneous coronary intervention (PCI).

The probability of death was adjusted for hypertension, diabetes mellitus with or without complications, obesity, valvular heart disease, peripheral vascular disease, pulmonary circulation disease, chronic obstructive pulmonary disease, renal failure, liver failure, coagulopathy, weight loss, fluid and electrolyte disorder, chronic blood loss anemia and alcohol abuse.

Central Illustration. Percutaneous coronary intervention in older adults with ST-elevation myocardial infarction and cardiogenic shock: 1999–2013.

The rates of utilization of percutaneous coronary intervention (PCI) in older patients with ST-elevation myocardial infarction (STEMI) and cardiogenic shock since the publication of the SHOCK trial results between 1999 and 2013.

Online Figure 1

Log-transformed probability of death by the propensity score. The graph illustrates a decrease in the risk of death at a propensity score [Pr(PCI) = 0.4]. As such a spline term at Pr(PCI) = 0.4 was chosen.