Lower heart rate response to apneic events was associated with higher cardiovascular risk in patients with resistant hypertension and OSA (adjusted HR 2.31; 95% CI 0.68-7.86; p=0.18).
Cohort (n=284)
Yes
Does a reduced heart rate response to apneic events predict cardiovascular events in patients with resistant hypertension and OSA?
In patients with resistant hypertension and OSA, a blunted heart rate response to apneic events may serve as a biomarker for increased long-term cardiovascular risk.
Effect estimate: adjusted HR 2.31 (95% CI 0.68-7.86)
p-value: p=0.18
Abstract Rationale Obstructive sleep apnea (OSA) is highly prevalent among patients with resistant hypertension (RH), a phenotype characterized by autonomic imbalance and increased cardiovascular morbidity. Recent clinical studies have identified two physiological markers, heart rate response to respiratory events (ΔHR) and hypoxic burden (HB), as quantifiers of OSA-related cardiovascular stress. While high ΔHR and HB identify “high-risk” OSA subgroups benefiting from continuous positive airway pressure (CPAP) in secondary prevention trials, the prognostic value of these metrics in untreated, real-world hypertensive populations remains unknown. Objectives To evaluate the association between baseline ΔHR and HB levels and long-term cardiovascular outcomes in patients with RH and OSA, and to determine whether combined phenotyping based on these metrics improves cardiovascular risk stratification. Methods The prospective SARAH study (NCT03002558) included 284 patients with RH recruited from specialized hypertension units. All participants underwent sleep testing and 24-hour ambulatory blood pressure monitoring at baseline and were followed annually. The primary endpoint was a composite of fatal and non-fatal cardiovascular events. Associations between ΔHR or HB quartiles and time to first event were analyzed using univariate and multivariable Cox regression. K-means clustering based on ΔHR and HB was used to derive distinct cardiovascular phenotypes. Measurements and Main Results A total of 132 non-CPAP patients median IAH 12.8 [IQR 8.2-18, median age 66 IQR 59-71 were analyzed (median follow-up 42 [IQR 32-59 months). Thirty-nine participants (21.8%) experienced a primary cardiovascular event. Lower ΔHR values were independently associated with higher cardiovascular risk (adjusted HR = 2.31 95% CI 0.68-7.86; p=0.18 for Q2 vs reference Q3), whereas HB quartiles showed no significant increased cardiovascular risk (Q4 vs Q1: adjusted HR = 1.52 0.48-4.74; p = 0.47). Cluster analysis (k = 3) combining ΔHR and HB identified a predominant phenotype (Cluster 2, 67.0%) with an a tendence to an increased cardiovascular risk (adjusted HR = 0.87 0.20-3.90; p = 0.86) compared with the reference group (Cluster 3, 28.6%) (Table). Conclusion In patients with resistant hypertension and OSA, a reduced heart rate response to apneic events reflecting blunted autonomic reactivity, was independently associated with an increased long-term cardiovascular risk, irrespective of hypoxic burden. These findings extend previous mechanistic observations from secondary-prevention OSA trials to a real-world hypertensive cohort, supporting ΔHR as a novel, readily obtainable biomarker for cardiovascular risk stratification beyond conventional sleep apnea metrics. This abstract is funded by: PI21/00337, PI24/01246, SBPLY/24/180225/000091
Amezcua et al. (Fri,) conducted a cohort in Resistant hypertension and obstructive sleep apnea (n=284). Heart rate response to respiratory events (ΔHR) and hypoxic burden (HB) vs. Higher ΔHR (reference Q3) or different clusters was evaluated on Composite of fatal and non-fatal cardiovascular events (adjusted HR 2.31, 95% CI 0.68-7.86, p=0.18). Lower heart rate response to apneic events was associated with higher cardiovascular risk in patients with resistant hypertension and OSA (adjusted HR 2.31; 95% CI 0.68-7.86; p=0.18).