Abstract Introduction A high resting heart rate (RHR) is an established risk factor for cardiovascular disease, adverse cardiac events, accelerated calcification in coronary artery disease and carotid stenosis, and increased aortic valve calcification in patients with and without a confirmed diagnosis of aortic stenosis (AS). Aortic valve calcification is the most common precursor to AS and is associated with significantly faster disease progression. There are few studies exploring the effects of RHR on the progression of AS, the development of severe stenosis, and the risk of complications and death. Purpose We hypothesised that an elevated RHR would be associated with poorer outcomes and more rapid haemodynamic disease progression in patients with AS and tested this in a large cohort of patients without severe disease. Methods Using the National Echocardiography Database of Australia (NEDA) we undertook a retrospective observational study on patients without severe AS, a bicuspid aortic valve or prior aortic valve replacement. The association between baseline RHR and time to the composite primary endpoint of severe AS, aortic valve replacement or cardiovascular death was tested using Cox proportional hazards regression. In addition, the relationship between baseline RHR and the components of this composite was investigated. Subsequently, the relationship between annualised AS progression rate, defined as change in standard indices of AS severity (maximal jet velocity [Vmax], mean pressure gradient [MPG], and aortic valve area [AVA]), and RHR were analysed using general linear models. Results The initial study cohort comprised 55 585 individuals: 54% male, mean age 63 years and median baseline RHR 70 bpm. The composite primary endpoint, reached by 7 434 patients, was independently associated with RHR (hazard ratio [per 10bpm increase], 1.04; 95% CI, 1.02-1.05; p < 0.001). RHR was also independently associated with time to developing severe AS (hazard ratio [per 10bpm increase], 1.06; 95% CI, 1.01-1.12; p = 0.017) and cardiovascular death (hazard ratio [per 10bpm increase], 1.04; 95% CI, 1.02-1.06; p < 0.001). The event rate was significantly higher in patients with a RHR of at least 70 bpm (the median RHR) compared to those with an RHR less than 70 bpm. In addition, RHR was independently associated with rate of change of each individual measurement index of AS severity including Vmax (β = 0.65 cm/s/year [per 10 bpm increase]; p < 0.001), MPG (β = 0.05 mmHg/ year [per 10 bpm increase]; p<0.001), and AVA (β = -0.01 cm2/year [per 10 bpm increase]; p < 0.001). Conclusions RHR is independently associated with adverse clinical outcomes and haemodynamic progression of AS in patients without severe disease. Future randomised controlled trials should investigate the effect of lowering RHR on clinical endpoints and progression of AS.
Read full abstract