Myocardial infarction after acute ischaemic stroke: incidence, mortality, and risk factors

Objectives: To determine the risk factor profiles associated with post-acute ischaemic stroke (AIS) myocardial infarction (MI) over long-term follow-up. Methods: This observational study includes prospectively identified AIS patients (n=9840) admitted to a UK regional centre between January 2003-December 2016 (median follow-up: 4.72 years). Predictors of post-stroke MI during follow up were examined using logistic and Cox regression models for in-hospital and post-discharge events, respectively. MI incidence was determined using a competing risk non-parametric estimator. The influence of post-stroke MI on mortality was examined using Cox regressions. Results: Mean age (SD) of study participants was 77.3(12.2) years (48% males). Factors associated with in-hospital MI (OR(95%CI)) were increasing blood glucose (1.80(1.17-2.77) per 10mmol/L), total leukocyte count (1.25(1.01-1.54) per 10x109/L), and CRP (1.05(1.02-1.08) per 10mg/L increase). Age (HR(95%CI) =1.03(1.01-1.06)), coronary heart disease (1.59(1.01-2.50)), chronic kidney disease (2.58(1.44-4.63)), and cancers (1.76(1.08-2.89)) were associated with incident MI between discharge and one year follow-up. Age ((1.02(1.00-1.03)), diabetes (1.96(1.38-2.65)), congestive heart failure (2.07(1.44-2.99), coronary heart disease (1.81(1.31-2.50)), hypertension (1.86(1.24-2.79)), and peripheral vascular disease (2.25(1.40-3.63)) were associated with incident MI between 1-5 years after discharge. Diabetes (2.01(1.09-3.72)), hypertension (3.69(1.44-9.45)), and peripheral vascular disease (2.46(1.02-5.98)) were associated with incident MI between 5-10 years after discharge. Cumulative MI incidence over 10 years was 5.4%. MI during all follow-up periods (discharge-1 year, 1-5 years, 5-10 years) was associated with increased risk of death (respective HR(95%CI)=3.26(2.51-4.15), 1.96(1.58-2.42) and 1.92(1.26-2.93)). Conclusions: In conclusion, prognosis is poor in post-stroke MI. We highlight a range of potential areas to focus preventative efforts.