[Relationship between baseline heart rate and all-cause death in general population]

To investigate the relationship between baseline heart rate(HR) and all-cause death(ACD)in general population.

93 716 workers with heart rate between 40 bpm/min-120 bpm/min and without histories of stroke were selected from the '2006-2007 health examination records' in Kailuan and completed the electrocardiogram exam. Related information were also gathered. These subjects were followed up from July 2006 to December 2010, with the mean time of follow-up as 47.5±4.3 months. During the follow-up period, the occurrence of all-cause death was observed every half a year.

(1)The lowest cumulative mortality rate was 1.61% in the group with 60-69 bpm/min. The lowest cumulative mortality rate was 1.78% in the group of 60-69 bpm/min in men. There was no death events observed in women with less than 50 bpm/min and the lowest cumulative mortality rate was 0.60% in the group of 80-89 bpm/min in women. (2)Data from Cox proportional hazard regression analysis showed that the RR(95%CI)of cumulative mortality rates in general population were 1.187 (1.039-1.336), 1.392(1.185-1.636), 1.733(1.404-2.139)and 2.716 (2.171-3.398)in the groups of 70-79, 80-89, 90-99 and ≥100 bpm/min, respectively. The RRs (95% CI) of cumulative mortality in men were 1.227(1.067-1.410), 1.481(1.254-1.750), 1.754 (1.406-2.188)and 2.831 (2.245-3.571) respectively. In women, when comparing with the group of 80-89 bpm/min, the RRs (95%CI)of all-cause death were 0.671(0.568-0.793), 0.825(0.703-0.970) and 1.925 (1.512-2.453)respectively in the groups of 60-69, 70-79 and ≥100 bpm/min.

When HR exceeding ≥70 bpm/min, the increase of HR would also increase the rate of ACD. Results of our study also showed a J-shaped curve relation between HR and mortality.