Predicting mortality in cardiogenic shock secondary to ACS requiring short-term mechanical circulatory support: The ACS-MCS score

Abstract

Objective: To identify predictors of 30-day all-cause mortality for patients with cardiogenic shock secondary to acute coronary syndrome (ACS-CS) who require short-term mechanical circulatory support (ST-MCS).

Background: ACS-CS mortality is high. ST-MCS is an attractive treatment option for hemodynamic support and stabilization of deteriorating patients. Mortality prediction modeling for ACS-CS patients requiring ST-MCS has not been well-defined.

Methods: The Utah Cardiac Recovery (UCAR) Shock database was used to identify patients admitted with ACS-CS requiring ST-MCS devices between May 2008 and August 2018. Pre-ST-MCS clinical, laboratory, echocardiographic, and angiographic data were collected. The primary endpoint was 30-day all-cause mortality. A weighted score comprising of pre-ST-MCS variables independently associated with 30-day all-cause mortality was derived and internally validated.

Results: A total of 159 patients (mean age, 61 years; 78% male) were included. Thirty-day all-cause mortality was 49%. Multivariable analysis resulted in four independent predictors of 30-day all-cause mortality: age, lactate, SCAI CS classification, and acute kidney injury. The model had good calibration and discrimination (area under the receiver operating characteristics curve 0.80). A predictive score (ranging 0-4) comprised of age ≥ 60 years, pre-ST-MCS lactate ≥2.5 mmol/L, AKI at time of ST-MCS implementation, and SCAI CS stage E effectively risk stratified our patient population.

Conclusion: The ACS-MCS score is a simple and practical predictive score to risk-stratify CS secondary to ACS patients based on their mortality risk. Effective mortality risk assessment for ACS-CS patients could have implications on patient selection for available therapeutic strategy options.

Keywords: acute coronary syndrome; cardiogenic shock; mechanical circulatory support.

Figure 1:

Performance of the ACS-MCS risk score on discriminating 30-day all-cause mortality. ROC: receiver operating characteristic.

Figure 2:

Predicted and observed 30-day all-cause mortality according to the ACS-MCS risk score.

Figure 3:

Kaplan-Meier curve for the occurrence of all-cause mortality within the 30-day follow-up period stratified by risk score: low risk (ACS-MCS score 0–1), intermediate risk (ACS-MCS score 2), and high-risk (ACS-MCS score 3–4).

Figure 4:

The ACS-MCS score as a useful tool in the contemporary management of cardiogenic shock (CS) secondary to acute coronary syndromes (ACS) in tertiary care centers. SCAI: Society for Cardiovascular Angiography and Interventions, AKI: Acute kidney injury.