Predictors of Sudden Cardiac Death Change With Time After MI
Predictors of Sudden Cardiac Death Change With Time After MI
Aims To determine whether predictors of sudden cardiac death (SCD) vary with time after myocardial infarction (MI).
Methods and results We analysed 11 256 patients enrolled in VALIANT. Landmark analysis and Cox proportional hazards modelling were used to predict SCD during hospitalization, from discharge to 30 days, 30 days to 6 months, and 6 months to 3 years. The cumulative incidence of SCD was 8.6% (n = 965). Initially, higher baseline heart rate [HR 1.20 per 10 b.p.m. (95% CI 1.06–1.37)] and impaired baseline creatinine clearance [HR 0.82 per 10 mL/min (95% CI 0.74–0.91)] were stronger predictors of SCD. With long-term follow-up, prior MI [HR 1.71 (95% CI 1.39–2.10)], initial left ventricular ejection fraction <40% [HR 0.67 per 10% (95% CI 0.58–0.78)], and recurrent cardiovascular events [HR 1.47 for rehospitalization (95% CI 1.17–1.86)] were more robust risk stratifiers for SCD. Atrial fibrillation post-MI was associated with an increased risk of SCD over the entire follow-up period. As time passed, the associations between baseline clinical characteristics and SCD decreased and time-updated assessments became more important.
Conclusion Predictors of SCD change with time after MI. Future studies of risk stratification for SCD should account for changes in these factors with time after MI.
Despite improvements in the care of patients with acute coronary syndromes, sudden cardiac death (SCD) remains a lethal complication of myocardial infarction (MI). The risk of SCD after MI is most pronounced in patients with heart failure (HF) and left ventricular (LV) dysfunction. The VALsartan In Acute myocardial iNfarcTion trial (VALIANT) Trial, which enrolled patients with acute MI complicated by LV dysfunction and/or HF demonstrated that the risk of SCD changes with time after MI, and that the risk of SCD is greatest in the first 30 days following MI. Despite this observation, both prospective and retrospective studies of implantable cardioverter defibrillators have failed to show a reduction in all-cause mortality in the days to first month after MI. This discrepancy reflects the limits of current risk stratification techniques and highlights the need for an improved understanding of the factors which contribute to SCD and their temporal relation after MI, particularly in patients with HF.
While many risk factors for SCD have been described, little is known about whether and how predictors of SCD vary with time after MI. Better understanding of the predictors of SCD as a function of time may allow for improved risk stratification and prevention of SCD. We conducted a retrospective study of SCD in the VALIANT trial using landmark follow-up periods after MI to identify predictors of SCD as a function of time.
Abstract and Introduction
Abstract
Aims To determine whether predictors of sudden cardiac death (SCD) vary with time after myocardial infarction (MI).
Methods and results We analysed 11 256 patients enrolled in VALIANT. Landmark analysis and Cox proportional hazards modelling were used to predict SCD during hospitalization, from discharge to 30 days, 30 days to 6 months, and 6 months to 3 years. The cumulative incidence of SCD was 8.6% (n = 965). Initially, higher baseline heart rate [HR 1.20 per 10 b.p.m. (95% CI 1.06–1.37)] and impaired baseline creatinine clearance [HR 0.82 per 10 mL/min (95% CI 0.74–0.91)] were stronger predictors of SCD. With long-term follow-up, prior MI [HR 1.71 (95% CI 1.39–2.10)], initial left ventricular ejection fraction <40% [HR 0.67 per 10% (95% CI 0.58–0.78)], and recurrent cardiovascular events [HR 1.47 for rehospitalization (95% CI 1.17–1.86)] were more robust risk stratifiers for SCD. Atrial fibrillation post-MI was associated with an increased risk of SCD over the entire follow-up period. As time passed, the associations between baseline clinical characteristics and SCD decreased and time-updated assessments became more important.
Conclusion Predictors of SCD change with time after MI. Future studies of risk stratification for SCD should account for changes in these factors with time after MI.
Introduction
Despite improvements in the care of patients with acute coronary syndromes, sudden cardiac death (SCD) remains a lethal complication of myocardial infarction (MI). The risk of SCD after MI is most pronounced in patients with heart failure (HF) and left ventricular (LV) dysfunction. The VALsartan In Acute myocardial iNfarcTion trial (VALIANT) Trial, which enrolled patients with acute MI complicated by LV dysfunction and/or HF demonstrated that the risk of SCD changes with time after MI, and that the risk of SCD is greatest in the first 30 days following MI. Despite this observation, both prospective and retrospective studies of implantable cardioverter defibrillators have failed to show a reduction in all-cause mortality in the days to first month after MI. This discrepancy reflects the limits of current risk stratification techniques and highlights the need for an improved understanding of the factors which contribute to SCD and their temporal relation after MI, particularly in patients with HF.
While many risk factors for SCD have been described, little is known about whether and how predictors of SCD vary with time after MI. Better understanding of the predictors of SCD as a function of time may allow for improved risk stratification and prevention of SCD. We conducted a retrospective study of SCD in the VALIANT trial using landmark follow-up periods after MI to identify predictors of SCD as a function of time.