Early revascularization is beneficial across all ages and a wide spectrum of cardiogenic shock severity: A pooled analysis of trials

Abstract

Background: A pooled analysis in cardiogenic shock due to acute coronary syndromes is desirable to assess the effect of early revascularization (ERV) across all ages and a wide spectrum of disease severity.

Methods: Only two randomized controlled trials (RCT), i.e. SMASH and SHOCK, met the inclusion criteria and were combined for a pooled analysis using individual patient data (n = 348).

Results: SMASH patients (n = 54, 16%) had more severe disease than SHOCK patients (n = 294, 84%). After adjustment for age, anoxic brain damage, non-inferior myocardial infarction, prior coronary artery bypass graft surgery, renal failure, systolic blood pressure, and selection for coronary angiography, one-year mortality was similar (relative risk SHOCK versus SMASH 0.87, 95% CI: 0.61–1.25). Relative risk of one-year death for ERV versus initial medical stabilization was 0.82 (95% CI: 0.70–0.96). There was no significant difference in the treatment effect by age (≤75 years relative risk at one year 0.79, 95% CI: 0.63–0.99; > 75 years relative risk at one year 0.93, 95% CI: 0.56–1.53; interaction P = 0.10).

Conclusions: Only two RCT have been published emphasizing the difficulty of enrolling critically ill patients. Despite large differences in shock severity, ERV benefit is similar across all ages and not significantly different for the elderly.

Keywords::

• Shock
• cardiogenic
• meta-analysis
• myocardial revascularization
• age factors
• comorbidity

Acknowledgements

The SHOCK trial was supported by RO1 grants HL49970, 1994–2005, and HL50020, 1994–1999, from the National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD. The SMASH trial was supported by the Swiss Cardiology Foundation, Bristol-Myers Squibb AG, Switzerland, Schneider-Worldwide, Arteromed SA, Medtronic Europe, and Coo (Switzerland) AG. Dr Jeger was supported by the AstraZeneca Scholarship of the Swiss Society of Hypertension, Switzerland; the Freiwillige Akademische Gesellschaft, Basel, Switzerland; and the Fund for the Promotion of a new Generation of Academics at the University of Basel, Basel, Switzerland.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.