P5642A clinical risk score for estimating sudden cardiac death risk in the general population
Abstract Background Sudden cardiac death (SCD) remains a major cause of premature mortality worldwide, so there has been an ongoing pursuit for tools for SCD risk stratification. Coronary artery disease is the major cause for SCD in adults, but the level of risk associated with multiple cardiovascular risk factors is not well established. Purpose To create a clinical risk score for estimating SCD risk in the general population. Methods Using data from a Finnish general population cohort of 7200 adults (mean age 51y, 46% male) with a mean follow-up of 24±11 years, we assessed the incremental SCD risk associated with the presence of several cardiovascular risk factors. SCD events were adjudicated based on death certificates according to the established criteria (autopsy was performed on 48% of SCD cases). Hazard ratios (HR) for SCD and all-cause mortality were calculated using the Cox proportional hazards model. Of the multiple parameters analysed, male sex, increasing age, diabetes, hypertension, smoking and previously diagnosed cardiac disease were independently associated with SCD in a multivariable model. Based on the magnitude of risk, a SCD risk score was created (2 points: age >70y; 1 point: male sex, age 60–70y, diabetes, hypertension, smoking, cardiac disease). Results 75.2% of the study subjects had 0–2 risk points, 12.8% 3 risk points, and 12.0% >3 risk points. During the follow-up, 400 SCDs occurred. Increasing risk score was associated with a progressively greater risk for SCD (Figure). Compared with subjects without risk factors, those with a risk score of 3 had a HR of 21.2 (95% CI 12.7–35.4, p<0.001) and those with a risk score of >3 had a HR of 52.6 (95% CI 31.3–88.3, p<0.001) for SCD. Clinical risk score predicted significantly also all-cause mortality (HR 31.5 with risk score >3 [95% CI 27.6–35.9, p<0.001]). Risk of SCD according to the risk score Conclusions Accumulation of multiple cardiovascular risk factors is associated with a markedly elevated risk for SCD in the general population. This highlights the need for SCD prevention efforts with lifestyle interventions and medical therapy in the high-risk subjects. Studies on focused SCD risk stratification may be warranted in the subjects at highest risk.