Sleep Apnea Evolution and Left Ventricular Recovery After Percutaneous Coronary Intervention for Myocardial Infarction.

STUDY OBJECTIVES: Sleep apnea is often newly diagnosed in patients presenting with ST-segment elevation myocardial infarction (STEMI). We assessed longitudinal changes in apnea-hypopnea index (AHI) and sleep apnea phenotype after STEMI and determined its association with changes in the left ventricular ejection fraction (LVEF). METHODS: A total of 101 eligible patients with STEMI underwent consecutive sleep studies and echocardiographic studies within 5 days of admission and at 6-month follow-up. Sleep apnea (AHI ≥ 15 events/h) was further divided into obstructive sleep apnea (OSA) or central sleep apnea (CSA). RESULTS: Both AHI (mean difference -6.4 events/h, 95% confidence interval [CI] -9.6 to 3.3, P < .001) and LVEF (mean difference 2.6%, 95% CI 1.3 to 4.0, P < .001) improved from baseline to 6 months. The improvement in AHI was associated with an increase in LVEF (ß = -.47, 95% CI -.86 to -.07, P = .023) and a decrease in left ventricular end-systolic volume (LVESV) (ß = .25, 95% CI .07 to .43, P = .007). Of the patients with OSA at baseline (46%), resolution of OSA was seen in 48% at 6 months. Of those with CSA at baseline (12%), conversion to OSA was seen in 83%. In contrast, among those with no sleep apnea (42%) at baseline, the diagnosis remained the same in 93% at 6 months. CONCLUSIONS: Concurrent changes in AHI, LVEF, and LVESV were seen after STEMI. Sleep studies performed on admission are reliable in excluding sleep apnea. However, patients with OSA or CSA on admission warrant re-evaluation due to evolution of the sleep apnea phenotype.

Watch-PAT versus level III device in diagnosing sleep disordered breathing in first myocardial infarction.

BACKGROUND: Watch-PAT 200, a novel portable sleep device worn on the wrist, has been validated against polysomnography. Although sleep disordered breathing (SDB) screening is recommended in patients with cardiovascular disease, no study has reported a comparison of results from Watch-PAT 200 and level III portable devices. METHODS: Patients (n = 140) admitted with a first ST-segment elevation myocardial infarction (STEMI) participated in a hospital-based sleep study using the Watch-PAT 200 and a level III portable device (Embletta Gold) simultaneously within five days of admission. SDB was defined as an apnea-hypopnea index (AHI) of >15 events/h. RESULTS: The left ventricular ejection fraction was normal (≥50%), impaired (30%-49%) and poor (<30%) in 66 (47.1%), 71 (50.7%), and three (2.2%) patients, respectively. Among 116 patients with a successful paired sleep study, the prevalence of SDB was 53.5% (Watch-PAT 200) and 51.7% (Embletta Gold). The agreement of AHI measured by the two devices was moderately good, with an intra-class correlation value of 0.72 (95% confidence interval, 0.62-0.80; P < .01). Agreement between the two devices in diagnosing at least mild (AHI ≥5), moderate-to-severe (AHI ≥15) and severe (AHI ≥30) SDB was 78% (kappa 0.47; P < .01), 77% (kappa 0.55; P < .01) and 80% (kappa 0.49; P < .01), respectively. At a 15-month follow-up, SDB status based on the two devices was associated with the occurrence of adverse cardiovascular events in 48.3% and 44.8%, respectively (P = .56). CONCLUSION: We found a high prevalence of SDB in patients presenting with a first STEMI. Agreement between two portable sleep devices was moderately good.

Factors associated with vascular stiffness: cross-sectional analysis from the Chronic Renal Insufficiency Standards Implementation Study.

BACKGROUND: Vascular stiffness is associated with increased cardiovascular risk. This study aimed to identify factors associated with vascular stiffness in a cohort of chronic kidney disease (CKD) patients. METHODS: The Chronic Renal Insufficiency Standards Implementation Study is a prospective epidemiological study of CKD patients not on dialysis, who are managed in a clinic setting. Phenotypic parameters were collected annually, and vascular stiffness was assessed using augmentation index (AI). Cross-sectional analysis was performed across quintiles of AI to evaluate factors associated with vascular stiffness. RESULTS: Mean patient age was 66.1 +/- 14.1 years and estimated glomerular filtration rate (eGFR) was 31.2 +/- 5.7 ml/min. Corrected calcium was 2.26 +/- 0.2 SD mmol/l, phosphate 1.2 +/- 0.4 SD mmol/l and intact parathyroid hormone 94 +/- 96 SD pg/ml; 18.3% of patients had cardiovascular disease. Increased age and systolic blood pressure were associated with increased AI (all p < 0.001). No statistical association was present between AI and eGFR, intact parathyroid hormone, phosphate or protein excretion. CONCLUSION: This study identified blood pressure as a potentially modifiable risk factor associated with AI, whereas eGFR was not associated with increased AI in a population of CKD stage 3-5 patients. Further knowledge of factors which influence progression of vascular stiffness will be important in risk quantification and management.