Carlson, Nicholas4; Dixen, Ulrik1; Marott, Jacob L2; Jensen, Magnus T5; Jensen, Gorm B1
1 Department of Cardiology, Medical Center, Amager and Hvidovre Hospital, The Capital Region of Denmark2 Arbejds- og miljømedicinsk klinik, Bispebjerg and Frederiksberg Hospital, The Capital Region of Denmark3 Copenhagen City Heart Study, Bispebjerg and Frederiksberg Hospital, The Capital Region of Denmark4 Department of Cardiology, Copenhagen University Hospital Herlev, The Copenhagen City Heart Study, Copenhagen University Hospital , Bispebjerg.5 Cardiology, Herlev and Gentofte Hospital, The Capital Region of Denmark
BACKGROUND: Elevated resting heart rate (RHR) is associated with cardiovascular mortality and morbidity. Assessment of heart rate (HR) from Holter recording may afford a more precise estimate of the effect of RHR on cardiovascular risk, as compared to casual RHR. Comparative analysis was carried out in an age-stratified subsample of 131 subjects in the Copenhagen City Heart Study (CCHS). METHODS: Casual RHR was assessed from electrocardiograms recorded during clinical assessment. Hourly daytime HRs were mapped by Holter recording. Holter RHR was defined as the average of the lowest 3 hourly HRs recorded and mean HR calculated from all daytime HRs. Follow-up was recorded from public registers. Outcome measure was hazard rate for the combined endpoint of cardiovascular mortality, non-fatal heart failure and non-fatal acute myocardial infarction. Comparison of casual RHR, Holter RHR and mean HR by Multivariate Cox regression was performed. RESULTS: A total of 57 composite endpoints occurred during 17.1 years of follow-up. Regression analysis suggests correlation between Casual RHR and Holter RHR. Multivariate Cox regression analysis adjusted for gender and age demonstrated hazard rates of 1.02 (p = 0.079) for casual RHR, 1.04 (p = 0.036*) for Holter RHR, and 1.03 (p = 0.093) for mean HR for each 10 beat increment in HR. CONCLUSIONS: In a comparative analysis on the correlation and significance of differing RHR measurement modalities RHR measured by 24-hour Holter recording was found to be marginally superior as a predictor of cardiovascular morbidity and mortality. The results presented here do not however warrant the abandonment of a tested epidemiological variable.
Scandinavian Journal of Clinical and Laboratory Investigation, 2014, Vol 74, Issue 2, p. 163-9