Background: Mitral annular calcification (MAC) and aortic valvular calcification (AVC) are progressive and linked to increased cardiovascular disease (CVD) morbidity and mortality. Few known modifiable risk factors associated with the progression of MAC and AVC exist. Resting heart rate (RHR) is an established independent risk factor for CVD. Due to the potential hemodynamic effects of RHR on development or progression of valve calcification, we assessed whether RHR is associated with the incidence and progression of MAC and AVC in a community-based cohort free of CVD and atrial fibrillation at baseline.
Methods: We obtained RHR from baseline 12-lead electrocardiograms of 5,498 MESA cohort participants. We studied RHR as a continuous variable (per 1 SD increment) and also categorized at clinical cut points of < 60, 60 - 69, 70 - 79, and ≥ 80 bpm. MAC and AVC were quantified (using Agatston scoring) from cardiac computed tomography scans obtained at baseline and at follow-up examinations 2 or 3. We examined associations between RHR and incident MAC/AVC and annual change in MAC/AVC scores, after adjusting for demographics, CVD risk factors, physical activity, and atrioventricular nodal blocker medication use. We used progressively adjusted parametric survival models for incident MAC/AVC and linear regression models for annual change in MAC/AVC.
Results: At baseline, participants had a mean age of 62±10 years and mean RHR of 63±10 bpm; 12.3% and 8.9% had prevalent AVC and MAC [Agatston Units (AU) >0], respectively. Over a median follow up time of 2.3 years, 4.1% and 4.5% developed incident AVC and MAC, respectively. Each 10 bpm higher RHR was significantly associated with incident MAC [Hazard Ratio 1.18 (95% CI 1.03-1.36)], but not incident AVC. However, RHR (per 10 bpm) was associated with AVC progression [β coeff 1.62 (0.45-2.80) AU/year], but not MAC progression. The association of RHR on annual change in AVC was modified by age and sex (p-interactions 0.006 and <0.02, respectively) but not race/ethnicity. Each 10 bpm higher RHR was significantly associated with AVC progression for age > 62 years [β coeff 2.94 (0.55, 5.34) AU/year] and male sex [3.49 (1.31, 5.67) AU/year]. The association between RHR and AVC progression was not significant for age ≤ 62 or female sex. Similar trends were seen using clinical cut-points for RHR.
Conclusion: Higher RHR predicted incident MAC and AVC progression independent of traditional CVD risk factors. Future studies are needed to determine whether this association is causal and whether modification of RHR through lifestyle or pharmacologic interventions can reduce valvular calcium progression.