Cardiorespiratory fitness and heart rate recovery predict sudden cardiac death independent of ejection fraction. Issue 6 (17th August 2019)

• Record Type: Journal Article
• Authors: Hernesniemi, Jussi A; Sipilä, Kalle; Tikkakoski, Antti; Tynkkynen, Juho T; Mishra, Pashupati P; Lyytikäinen, Leo-Pekka; Nikus, Kjell; Nieminen, Tuomo; Lehtimaki, Terho; Kähönen, Mika
• Is Part Of: Heart. Volume 106:Issue 6(2020)
• Page Start: 434
• Page End: 440
• Publication Date: 2019-08-17
• Subjects: echocardiography -- cardiac arrest -- ECG -- cardiac imaging and diagnostics; Heart -- Diseases -- Treatment -- Periodicals; Cardiology -- Periodicals; 616.12
• DOI: 10.1136/heartjnl-2019-315198
• Languages: English
• ISSNs: 1355-6037

Abstract

Abstract : Objective: To evaluate whether cardiorespiratory fitness (CRF) and heart rate recovery (HRR) associate with the risk of sudden cardiac death (SCD) independently of left ventricular ejection fraction (LVEF). Methods: The Finnish Cardiovascular Study is a prospective clinical study of patients referred to clinical exercise testing in 2001–2008 and follow-up until December 2013. Patients without pacemakers undergoing first maximal or submaximal exercise testing with cycle ergometer were included (n=3776). CRF in metabolic equivalents (METs) was estimated by achieving maximal work level. HRR was defined as the reduction in heart rate 1 min after maximal exertion. Adjudication of SCD was based on death certificates. LVEF was measured for clinical indications in 71.4% of the patients (n=2697). Results: Population mean age was 55.7 years (SD 13.1; 61% men). 98 SCDs were recorded during a median follow-up of 9.1 years (6.9–10.7). Mean CRF and HRR were 7.7 (SD 2.9) METs and 25 (SD 12) beats/min/min. Both CRF and HRR were associated with the risk of SCD in the entire study population (HRCRF 0.47 (0.37–0.59), p<0.001 and HRHRR 0.57 (0.48–0.67), p<0.001 with HR estimates corresponding to one SD increase in the exposure variables) and with CRF, HRR and LVEF in the same model (HRCRF 0.60 (0.45–0.79), p<0.001, HRHRR 0.65 (0.51–0.82), p<0.001) or adjusting additionally for all significant risk factors for SCD (LVEF, sex, creatinine level, history of myocardial infarction and atrial fibrillation, corrected QT interval) (HRCRF 0.69 (0.52–0.93), p<0.01, HRHRR 0.74 (0.58–0.95) p=0.02). Conclusions: CRF and HRR are significantly associated with the risk of SCD regardless of LVEF.