The Long-Term Prognostic Role of Nighttime Resting Heart Rate in Obstructive Sleep Apnea in Patients with Acute Coronary Syndrome.

AIM: A close relationship exists between resting heart rate (RHR) and obstructive sleep apnea (OSA). Still, the prognostic importance of nighttime RHR in patients with acute coronary syndrome (ACS) with or without OSA remains unclear. METHODS: In this prospective cohort study, OSA was defined as an apnea-hypopnea index of ≥ 15 events/h, and the high nighttime RHR (HNRHR) was defined as a heart rate of ≥ 70 bpm. The primary endpoint was a major adverse cardiovascular and cerebrovascular event (MACCE), including cardiovascular death, myocardial infarction, stroke, ischemia-driven revascularization, or hospitalization for heart failure. RESULTS: Among the 1875 enrolled patients, the mean patient age was 56.3±10.5 years, 978 (52.2%) had OSA, and 425 (22.7%) were in HNRHR. The proportion of patients with HNRHR is higher in the OSA population than in the non-OSA population (26.5% vs. 18.5%; P＜0.001). During 2.9 (1.5, 3.5) years of follow-up, HNRHR was associated with an increased risk of MACCE in patients with OSA (adjusted HR: 1.56, 95% CI: 1.09-2.23, P=0.014), but not in patients without OSA (adjust HR: 1.13, 95% CI: 0.69-1.84, P=0.63). CONCLUSIONS: In patients with ACS, a nighttime RHR of ≥ 70 bpm was associated with a higher risk of MACCE in those with OSA but not in those without it. This identifies a potential high-risk subgroup where heart rate may interact with the prognosis of OSA. Further research is needed to determine causative relationships and confirm whether heart rate control impacts cardiovascular outcomes in patients with ACS-OSA.

Pde5 Inhibition Reduced Blood Pressure and Alleviated Target Organ Damage in Chronic Intermittent Hypoxia.

ABSTRACT: The role of phosphodiesterase 5 (Pde5) in obstructive sleep apnea (OSA) induced damage remains unclear. Our study aimed to investigate the role of Pde5 in chronic intermittent hypoxia (CIH) model. C57BL/6J wild-type (WT) mice (n=48) and Pde5 knockout (Pde5-/-) mice (n=24) were randomly assigned to CIH group and room air (RA) group. After 6 weeks, some WT mice (n=24) in CIH group were given sildenafil or saline gavage for another 4 weeks. Blood pressure was regularly measured during the experiment. Echocardiography was used to estimate cardiac function. We collected organs from each group of mice and measured their physical indicators. Histochemical staining was used to explore the size of cardiomyocyte and fibrosis area of various organs. Cyclic guanosine monophosphate (cGMP) and Malondialdehyde (MDA) concentrations in serum were measured by ELISA assay. Compared to the RA-treated group, the 6-week CIH resulted in a significant increase in blood pressure, altered heart structure and reduced serum cGMP in WT mice. Pde5-/- mice and sildenafil intragastric administration significantly reduced systolic blood pressure in CIH condition and attenuated the damage of target organs. In CIH model, we found that the cardiomyocyte size and fibrosis area of heart and kidney significantly reduced in Pde5-/- groups. Besides, endogenous and exogenous inhibition of Pde5 reduced MDA level and inflammatory and oxidative stress markers expression in CIH condition. In the present study, we found that Pde5 inhibition could reduce blood pressure and alleviate target organ damage in the CIH model, which may be mediated through the oxidative stress pathway.

Incorrect ECG Diagnoses?-Follow the Leads.

This case report describes a patient in their early 70s with frequent paroxysmal chest pain.