Nocturnal Oxygen Desaturation as a Predictive Risk Factor for Coronary Restenosis After Coronary Intervention Serial Quantitative Coronary Angiography Study

Lipid metabolism and neuromuscular junction as common pathways underlying the genetic basis of erectile dysfunction and obstructive sleep apnea

Erectile dysfunction (ED) incidence is higher in patients with obstructive sleep apnea (OSA). Studies have suggested that ED and OSA may activate similar pathways; however, few have investigated the links between their underlying genotypic profiles. Therefore, we conducted an in-silico analysis to test whether ED and OSA share genetic variants of risk and to identify any molecular, cellular and biological interactions between them. Two gene lists were manually curated through a literature review based on a PUBMED search, which resulted in one gene list associated with ED (total of 205 genes) and the other with OSA (total of 2622 genes). Between those gene sets, 35 were common for both lists (Fisher exact test, p-value = 0.027). The Protein-protein interaction (PPI) analysis using the intersect list as input showed that 3 of them had direct interactions (LPL, DGKB and PLCB1). In addition, the biological function of the genes contained in the intersect list suggested that pathways related to lipid metabolism and the neuromuscular junction were commonly found in the genetic basis of ED and OSA. From the shared genes between both conditions, the biological pathways highlighted in this study may serve as preliminary findings for future functional investigations on OSA and ED association.

High frequency of coronary artery ectasia in obstructive sleep apnea

STUDY OBJECTIVES

Patients with obstructive sleep apnea (OSA) have a greater risk of developing coronary artery disease. However, the frequency of specific coronary artery vascular phenotypes, such as coronary artery ectasia (CAE), which has a frequency of 5% in the general population, has not been studied in patients with OSA. This study aimed to estimate CAE frequency in patients with OSA who underwent coronary angiography.

METHODS

A retrospective cross-sectional study was performed. The results of each polysomnography were reviewed, classifying OSA severity according to the apnea-hypopnea index. Each coronary angiography was reviewed. CAE was defined and classified according to the scales described in the literature. Two groups of patients were classified and compared (OSA/CAE group vs OSA/non-CAE group).

RESULTS

We identified the frequency of CAE in 185 patients with OSA who underwent coronary angiography. The frequency of CAE was 18.4% in these patients. ST-elevation myocardial infarction as the indication for coronary angiography was significantly greater in the OSA/CAE group than the OSA/non-CAE group (26.5% vs 9.9%; P = .02); 62% of the patients having severe OSA (apnea-hypopnea index ≥ 30 events/h). These patients in the OSA/CAE group had a significantly higher median apnea-hypopnea index than in the OSA/non-CAE group (72.5 events/h vs 53.5 events/h, respectively; P = .039). The CAE severity was not directly related to the OSA severity.

CONCLUSIONS

The frequency of CAE in patients with OSA is higher than that reported for the general population. The severity of OSA is related to the presence of CAE but not to its severity.

CITATION

del Portillo JH, Hernandez BM, Bazurto MA, Echeverri D, Cabrales J. High frequency of coronary artery ectasia in obstructive sleep apnea. J Clin Sleep Med. 2022;18(2):433-438.

Influence of sleep-disordered breathing assessed by pulse oximetry on long-term clinical outcomes in patients who underwent percutaneous coronary intervention

BACKGROUND

Sleep-disordered breathing (SDB) has been recognized as an important risk factor for coronary artery disease (CAD). However, SDB was not fully examined, because sleep studies are limited. Nocturnal pulse oximetry has been suggested to be a useful tool for evaluating SDB. Therefore, the aim of this study was to investigate the influence of SDB assessed by nocturnal pulse oximetry on clinical outcomes in patients who underwent percutaneous coronary intervention (PCI).

METHODS

We conducted a prospective, multicenter, observational cohort study, wherein SDB was assessed by finger pulse oximetry in patients who underwent PCI from January 2014 to December 2016. SDB was defined as 4% oxygen desaturation index of 5 and higher. The primary endpoint was major adverse cardiac or cerebrovascular event (MACCE), defined as a composite of all-cause mortality, acute coronary syndrome, and/or stroke.

RESULTS

Of 539 patients, 296 (54.9%) had SDB. MACCE occurred in 32 patients (5.8%) during a median follow-up of 1.9 years. The cumulative incidence of MACCE was significantly higher in patients with SDB (P = 0.0134). In the stepwise multivariable Cox proportional model, the presence of SDB was a significant predictor of MACCE (hazard ratio 2.26; 95% confidence interval 1.05-5.4, P = 0.036).

CONCLUSIONS

SDB determined by nocturnal pulse oximetry was associated with worse clinical outcomes in patients who underwent PCI. Screening for SDB with nocturnal pulse oximetry was considered to be important for risk stratification in patients with CAD.

[Cardiac effects of obstructive sleep apnea]

Sleep disordered breathing, especially obstructive sleep apnea, are common in cardiovascular disease. Negative hemodynamic effects are mediated by nocturnal ischemia and intrathoracal pressure swings. Therefore "therapy resistant" arterial hypertension and congestive heart failure, as well as atrial fibrillation or sleep associated bradycardia are suggestive of sleep disordered breathing. Further on, clinical course of coronary artery disease seems to be influenced by nocturnal breathing disorders. Application of continuous positive airway pressure (CPAP) is effective in most of the patients and attenuates cardiodepressive hemodynamic effects of obstructive sleep apnea.

Impact of obstructive sleep apnea on the occurrence of restenosis after elective percutaneous coronary intervention in ischemic heart disease

Rationale

There is growing evidence that obstructive sleep apnea is associated with coronary artery disease. However, there are no data on the course of coronary stenosis after percutaneous coronary intervention in patients with obstructive sleep apnea.

Objectives

To determine whether sleep apnea is associated with increased late lumen loss and restenosis after percutaneous coronary intervention.

Methods

78 patients with coronary artery disease who underwent elective percutaneous coronary intervention were divided in 2 groups: 43 patients with an apnea hypopnea – Index < 10/h (group I) and 35 pt. with obstructive sleep apnea and an AHI > 10/h (group II). Late lumen loss, a marker of restenosis, was determined using quantitative coronary angiography after 6.9 ± 3.1 months.

Main results

Angiographic restenosis (>50% luminal diameter), was present in 6 (14%) of group I and in 9 (25%) of group II (p = 0.11). Late lumen loss was significant higher in pt. with an AHI > 10/h (0.7 ± 0.69 mm vs. 0.38 ± 0.37 mm, p = 0.01). Among these 35 patients, 21(60%) used their CPAP devices regularly. There was a marginally lower late lumen loss in treated patients, nevertheless, this difference did not reach statistical significance (0.57 ± 0.47 mm vs. 0.99 ± 0.86 mm, p = 0.08). There was no difference in late lumen loss between treated patients and the group I (p = 0.206).

Conclusion

In summary, patients with OSA and coronary artery disease have a higher degree of late lumen loss, which is a marker of restenosis and vessel remodeling after elective percutaneous intervention.

Decreased lipoprotein lipase in obstructive sleep apnea syndrome

BACKGROUND

Lipoprotein lipase (LPL) might play a major role in lipid metabolism by hydrolyzing triglyceride-rich lipoproteins. Decreased LPL activity can trigger early inflammatory responses central to atherosclerosis. However, whether repeated apnea-related hypoxemia influences lipid metabolism in patients with obstructive sleep apnea syndrome (OSAS) remain undefined. This investigation determined whether circulating LPL was influenced by repeated apnea-related hypoxemia, and the effect of nasal continuous positive airway pressure (CPAP) therapy on LPL concentrations in OSAS patients.

METHODS AND RESULTS

The participants of the study were 155 men with OSAS and 39 men without OSAS. Circulating LPL concentrations decreased with the severity of OSAS. They correlated negatively with serum triglyceride, and the linear regression lines between LPL concentrations and triglyceride in OSAS patients were shifted downward compared with those in non-OSAS patients, suggesting that any pathophysiological factor might decrease LPL activity in OSAS patients. Some OSAS patients were subjected to CPAP therapy for 3 months. CPAP therapy increased LPL concentrations and decreased C-reactive protein (CRP) concentrations.

CONCLUSIONS

The present study suggests that repeated apnea-related hypoxemia might affect lipid metabolism and augment inflammatory responses, and CPAP therapy could be effective to decrease inflammatory responses and ameliorate lipid metabolism in patients with OSAS.

Treatment of obstructive sleep apnea is associated with decreased cardiac death after percutaneous coronary intervention

OBJECTIVES

Our purpose was to compare outcomes of patients treated for obstructive sleep apnea (OSA) versus patients with untreated OSA, all of whom had undergone percutaneous coronary intervention (PCI).

BACKGROUND

Obstructive sleep apnea has been associated with increases in fatal and nonfatal cardiovascular events. It is not known whether treatment of OSA in patients who have had PCI results in a better outcome.

METHODS

In a retrospective cohort study, a group of patients with OSA diagnosed with polysomnography between 1992 and 2004 (apnea-hypopnea index > or =15) who subsequently underwent a PCI (n = 371) were stratified according to whether they were treated for OSA (n = 175) or not (n = 196). Main outcome measures were cardiac death, general mortality, major adverse cardiac events (MACE) (severe angina, myocardial infarction, PCI, coronary artery bypass grafting, or death), and major adverse cardiac or cerebrovascular events (MACCE).

RESULTS

Patients treated for OSA had a statistically significant decreased number of cardiac deaths on follow-up when compared with untreated OSA patients (3% [95% confidence interval (CI) 0% to 6%] vs. 10% [95% CI 5% to 14%] after 5 years, p = 0.027), as well as a trend toward decreased all-cause mortality (p = 0.058). There was no difference in the number of MACE or MACCE between the 2 groups (p = 0.91 and 0.96, respectively).

CONCLUSIONS

Treatment of OSA is associated with a reduction in the number of cardiac deaths, but not in MACE or MACCE, after PCI. Screening for and treating OSA in patients with coronary artery disease who may undergo PCI may result in decreased cardiac death.