Heart rate as an independent risk factor in patients with multiple organ dysfunction: a prospective, observational study

To study the association between baseline heart rate and outcome in patients with multiple organ dysfunction (MODS) as well as the course of heart rate over the first 4 days during MODS. Prospective observational study in 89 patients with MODS, defined as an APACHE-II score a parts per thousand yen20. Baseline heart rate (HR0) was determined over a 60-minute period at the time of MODS diagnosis. 28-day all-cause mortality was the primary endpoint of the study, a fall of the APACHE-II score by 4 points or more from day 0 to day 4 constituted the secondary endpoint. Hazard ratios for heart rate of 90 beats per minute (bpm) or greater relative to less than 90 bpm were calculated using Cox proportional hazards model and adjusted for confounding variables. Median baseline heart rate was 83 bpm in survivors and 92 bpm in non-survivors (p = 0.048). 28-day mortality was 32 and 61% in patients with HR0 < 90 bpm and HR0 a parts per thousand yen 90 bpm, respectively. The adjusted hazard ratio for 28-day mortality was 2.30 (95% confidence interval 1.21-4.36, p = 0.001) for HR0 a parts per thousand yen 90 bpm relative to HR0 < 90 bpm. No correlation was found between baseline heart rate and the secondary endpoint. From day 0 to day 4, heart rate remained elevated in all patients, as well as in survivors and non-survivors. A heart rate a parts per thousand yen90 bpm at the time of MODS diagnosis is an independent risk factor for increased 28-day mortality. As in patients with cardiovascular conditions such as coronary heart disease or chronic heart failure, heart rate might constitute a target for heart rate-lowering therapy in the narrow initial treatment window of MODS.