Background: The Mayo Clinic Risk Score (MCRS) is a validated numeric score that predicts outcome following primary percutaneous coronary intervention (PCI).
Purpose: We evaluated the ability of MCRS to risk stratify patients undergoing primary angioplasty.
Methods: Patients undergoing primary angioplasty within 6 hours of the onset of chest pain in the New York State percutaneous coronary intervention reporting system (n = 3,005) had their MCRS calculated using predictive variables: age, presence of cardiogenic shock, renal failure, class III-IV congestive heart failure, left main coronary disease and multivessel coronary disease. All patients were presumed to have intra-coronary thrombus and undergoing an urgent/emergent procedure. Based on the MCRS, patients were classified into five risk categories: very low-risk (MCRS < 5), low risk (6-8), moderate (9-11), high (12-14) and very high risk (15-25).
Results: The mean age of the study population was 62 years, 70% were male; stents were used in 89% and glycoprotein IIb/IIIa antagonists in 72%. The prevalence of cardiogenic shock, multivessel disease and left main disease was higher in patients with MCRS > 12. Overall in-hospital mortality following primary angioplasty was 4.7%; it was 0% in the very low-risk category, 0.9% in the low-risk category, 3.2% in the moderate-risk category, 10.7% in the high-risk category, and 25.1% in the very high-risk category (p < 0.0001). The higher-risk MCRS category predicted increased risk even when 317 (10.5%) patients with cardiogenic shock were excluded from the analysis. The overall c-statistic for the prediction of in-hospital mortality by MCRS was 0.85.
Conclusion: Increasing MCRS predicts in-hospital mortality following primary angioplasty.