Markers of Myocardial Ischemia in Patients With Coronary Artery Disease and Obstructive Sleep Apnea: Effect of Continuous Positive Airway Pressure Therapy

Abstract

Background: Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular complications. OSA and coronary artery disease (CAD) share the same risk factors and coexist in many patients. In previous studies, repeated nocturnal cardiac ischemic events in OSA patients with CAD have been reported. Hypothesis: We hypothesized that OSA may precipitate myocardial ischemia, evidenced by ST-segment depression and elevated N-terminal brain natriuretic peptide (NT-proBNP) and high-sensitivity troponin T (hs-TropT) levels in patients with severe OSA and concomitant CAD. We also aimed to evaluate if the effects could be reversed by continuous positive airway pressure (CPAP) therapy. Methods: Twenty-one patients with severe OSA (apnea-hypopnea index >15/h, nadir oxygen desaturation ≤80%), and coexisting CAD underwent in-hospital polysomnography at baseline and under CPAP. Blood samples for hs-TropT and NT-proBNP measurements were drawn prior and immediately after sleep. ST-segment depression was measured at the time of maximum oxygen desaturation during sleep. Results: CPAP significantly decreased elevated NT-proBNP levels from 475 ± 654 pg/mL before sleep to 353 ± 573 pg/mL after sleep and attenuated ST-segment depression during sleep. hs-TropT was not elevated and did not differ after nocturnal oxygen desaturation at baseline and after CPAP. Conclusions: CPAP significantly reduced NT-proBNP in patients suffering from severe OSA and coexisting CAD. Repeated nocturnal myocardial ischemia did not cause myocyte necrosis evidenced by elevated hs-TropT or ST-segment depression.

Sleep Apnea in Total Joint Arthroplasty Patients and the Role for Cardiac Biomarkers for Risk Stratification: an Exploration of Feasibility

“…In a small study of 21 patients with severe OSA and presence of CAD, Valo and colleagues found that levels of hs-cTnT drawn before and after sleep were not affected by one night of CPAP use [135]. Further, in this study, electrocardiogram monitoring of ST segments were conducted throughout the night of sleep to document any evidence of myocardial ischemia [135].…”

“…Further, in this study, electrocardiogram monitoring of ST segments were conducted throughout the night of sleep to document any evidence of myocardial ischemia [135]. Although use of CPAP reduced ST segment depression during the lowest point of oxygen desaturation with sleep, this finding was not significant.…”

“…Valo and colleagues observed, not only did a night of CPAP therapy reduce NT-proBNP levels in patients with severe OSA with presence of CAD, it decreased ST-segment depression monitored at the time of peak oxygen desaturation during sleep [135]. Koga et al, observed BNP levels decreased following 3 months of nasal CPAP [62].…”

“…Current evidence (see Table 3) primarily suggests that PAP adherence does not affect cTns [133][134][135] in the overall OSA population. However, one study showed a change in the levels of cTn, an increase in hs-cTnT levels with CPAP use [130].…”

“…The effects of PAP therapy on BNP levels have been mixed, with a number of studies demonstrating PAP did not significantly alter levels of BNPs [64,73,133,134] versus other studies observing PAP decreased levels of BNPs [62,69,135,149] (see Table 6). However, some evidence seems to suggest that significant changes in BNP levels with PAP therapy occurs, particularly in patients with OSA and known left ventricular dysfunction or who have pre-existing cardiovascular risk factors.…”