Oladipupo Olafiranye

Obstructive sleep apnea and dyslipidemia: evidence and underlying mechanism

IntroductionOver the past half century, evidence has been accumulating on the emergence of obstructive sleep apnea (OSA), the most prevalent sleep-disordered breathing, as a major risk factor for cardiovascular disease. A significant body of research has been focused on elucidating the complex interplay between OSA and cardiovascular risk factors, including dyslipidemia, obesity, hypertension, and diabetes mellitus that portend increased morbidity and mortality in susceptible individuals.ConclusionAlthough a clear causal relationship of OSA and dyslipidemia is yet to be demonstrated, there is increasing evidence that chronic intermittent hypoxia, a major component of OSA, is independently associated and possibly the root cause of the dyslipidemia via the generation of stearoyl-coenzyme A desaturase-1 and reactive oxygen species, peroxidation of lipids, and sympathetic system dysfunction. The aim of this review is to highlight the relationship between OSA and dyslipidemia in the development of atherosclerosis and present the pathophysiologic mechanisms linking its association to clinical disease. Issues relating to epidemiology, confounding factors, significant gaps in research and future directions are also discussed.

Obstructive sleep apnea and cardiovascular disease in blacks: A call to action from the Association of Black Cardiologists

Obstructive sleep apnea (OSA) has emerged as a new and important risk factor for cardiovascular disease (CVD). Over the last decade, epidemiologic and clinical research has consistently supported the association of OSA with increased cardiovascular (CV) morbidity and mortality. Such evidence prompted the American Heart Association to issue a scientific statement describing the need to recognize OSA as an important target for therapy in reducing CV risk. Emerging facts suggest that marked racial differences exist in the association of OSA with CVD. Although both conditions are more prevalent in blacks, almost all National Institutes of Health-funded research projects evaluating the relationship between OSA and CV risk have been conducted in predominantly white populations. There is an urgent need for research studies investigating the CV impact of OSA among high-risk minorities, especially blacks. This article first examines the evidence supporting the association between OSA and CVD and reviews the influence of ethnic/racial differences on this association. Public health implications of OSA and future directions, especially regarding minority populations, are discussed.

Management of Hypertension among Patients with Coronary Heart Disease

Evidence suggests that coronary heart disease (CHD) is the most common outcome of hypertension. Hypertension accelerates the development of atherosclerosis, and sustained elevation of blood pressure (BP) can destabilize vascular lesions and precipitate acute coronary events. Hypertension can cause myocardial ischemia in the absence of CHD. These cardiovascular risks attributed to hypertension can be reduced by optimal BP control. Although several antihypertensive agents exist, the choice of agent and the appropriate target BP for patients with CHD remain controversial. In this succinct paper, we examine the evidence and the mechanisms for the linkage between hypertension and CHD and we discuss the treatment options and the goals of therapy that are consistent with the report of the seventh Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) and American Heart Association scientific statement. We anticipate changes in the recommendations of the forthcoming JNC 8.

Feasibility of Remote Ischemic Peri-conditioning during Air Medical Transport of STEMI Patients

Abstract Remote ischemic peri-conditioning (RIPC) has gained interest as a means of reducing ischemic injury in patients with acute ST-elevation myocardial infarction (STEMI) who are undergoing emergent primary percutaneous coronary intervention (pPCI). We aimed to evaluate the feasibility, process, and patient-related factors related to the delivery of RIPC during air medical transport of STEMI patients to tertiary pPCI centers. We performed a retrospective review of procedural outcomes of a cohort of STEMI patients who received RIPC as part of a clinical protocol in a multi-state air medical service over 16 months (March 2013 to June 2014). Eligible patients were transported to two tertiary PCI centers and received up to four cycles of RIPC by inflating a blood pressure cuff on an upper arm to 200 mmHg for 5 minutes and subsequently deflating the cuff for 5 minutes. Data regarding feasibility, process variables, patient comfort, and occurrence of hypotension were obtained from prehospital records and prospectively completed quality improvement surveys. The primary outcome was whether at least 3 cycles of RIPC were completed by air medical transport crews prior to pPCI. Secondary outcomes included the number of cycles completed prior to pPCI, time spent with the patient prior to transport (bedside time), patient discomfort level, and incidence of hypotension (systolic blood pressure <90 mmHg) during the procedure. RIPC was initiated in 99 patients (91 interfacility, 8 scene transports) and 83 (83.3%) received 3 or 4 cycles of RIPC, delivered over 25–35 minutes. Median bedside time for interfacility transfers was 8 minutes (IQR 7, 10). More than half of patients reported no pain related to the procedure (N = 53, 53.3%), whereas 5 (5.1%) patients reported discomfort greater than 5 out of 10. Two patients developed hypotension while receiving RIPC and both had experienced hypotension prior to initiation of RIPC. RIPC is feasible and safe to implement for STEMI patients undergoing air medical transport for pPCI, without occurrence of prolonged bedside times. The incidence of excessive RIPC-related discomfort or hemodynamic instability is rare. STEMI patients requiring on average >30 minutes transport for pPCI may be the ideal group for RIPC utilization.

Functional capacity is a better predictor of coronary heart disease than depression or abnormal sleep duration in Black and White Americans

OBJECTIVE To assess whether functional capacity is a better predictor of coronary heart disease (CHD) than depression or abnormal sleep duration. METHODS Adult civilians in the USA (n=29,818, mean age 48 ± 18 years, range 18-85 years) were recruited by a cross-sectional household interview survey using multistage area probability sampling. Data on chronic conditions, estimated habitual sleep duration, functional capacity, depressed moods, and sociodemographic characteristics were obtained. RESULTS Thirty-five percent of participants reported reduced functional capacity. The CHD rates among White and Black Americans were 5.2% and 4%, respectively. Individuals with CHD were more likely to report extreme sleep durations (short sleep [≤ 5h] or long sleep [≥ 9 h]; odds ratio [OR] 1.65, 95% confidence interval [CI] 1.38-1.97; P<0.0001), less likely to be functionally active (anchored by the ability to walk one-quarter of a mile without assistance [OR 6.27, 95% CI 5.64-6.98; P<0.0001]) and more likely to be depressed (OR 1.78, 95% CI 1.60-1.99; P<0.0001) than their counterparts. On multivariate regression analysis adjusting for sociodemographic factors and health characteristics, only functional capacity remained an independent predictor of CHD (OR 1.81, 95% CI 1.42-2.31; P<0.0001). CONCLUSION Functional capacity was an independent predictor of CHD in the study population, whereas depression and sleep duration were not independent predictors.

The Relationship Between Effective Arterial Capacitance and Pulse Wave Velocity Is Dependent on Left Ventricular Stroke Volume

Background: increased arterial stiffness is a predictor of cardiovascular events. The stroke volume (SV) to pulse pressure (PP) ratio is an estimate of arterial capacitance. Pulse wave velocity (PWV) is a measure of arterial stiffness. This study evaluated the effect of left ventricular (LV) SV on the SV/PP—PWV relationship. Methods: 97 patients had applanation tonometry and echocardiography to measure arterial capacitance (SV/PP), PWV, and central aortic pressure. Results: 50 patients had normal SV and 47 had low SV. For all patients, PWV inversely correlated with SV/PP. PWV and SV/PP correlated more strongly in the normal SV group than in the low SV group. Aortic PP was significantly correlated with PWV in all patients, in the normal SV group, and in the low SV group. Conclusion: effective arterial capacitance correlates with PWV. The presence of decreased SV weakens the relationship.

Renal Protection Using Remote Ischemic Peri-Conditioning During Inter-Facility Helicopter Transport of Patients With ST-Segment Elevation Myocardial Infarction: A Retrospective Study

OBJECTIVE To assess the impact of remote ischemic peri-conditioning (RIPC) during inter-facility air medical transport of ST-segment elevation myocardial infarction (STEMI) patients on the incidence of acute kidney injury (AKI) following primary percutaneous coronary intervention (pPCI). BACKGROUND STEMI patients who receive pPCI have an increased risk of AKI for which there is no well-defined prophylactic therapy in the setting of emergent pPCI. METHODS Using the ACTION Registry-GWTG, we evaluated the impact of RIPC applied during inter-facility helicopter transport of STEMI patients from non-PCI capable hospitals to 2 PCI-hospitals in the United States between March, 2013 and September, 2015 on the incidence of AKI following pPCI. AKI was defined as ≥0.3 mg/dL increase in creatinine within 48-72 hours after pPCI. RESULTS Patients who received RIPC (n = 127), compared to those who did not (n = 92), were less likely to have AKI (11 of 127 patients [8.7%] vs. 17 of 92 patients [18.5%]; adjusted odds ratio = 0.32, 95% CI 0.12-0.85, P = 0.023) and all-cause in-hospital mortality (2 of 127 patients [1.6%] vs. 7 of 92 patients [7.6%]; adjusted odds ratio = 0.14, 95% CI 0.02-0.86, P = 0.034) after adjusting for socio-demographic and clinical characteristics. There was no difference in hospital length of stay (3 days [interquartile range, 2-4] vs. 3 days [interquartile range, 2-5], P = 0.357) between the 2 groups. CONCLUSION RIPC applied during inter-facility helicopter transport of STEMI patients for pPCI is associated with lower incidence of AKI and in-hospital mortality. The use of RIPC for renal protection in STEMI patients warrants further in depth investigation.

Particulate Matter Air Pollution and Racial Differences in Cardiovascular Disease Risk

Objective— We aimed to assess racial differences in air pollution exposures to ambient fine particulate matter (particles with median aerodynamic diameter <2.5 µm [PM2.5]) and black carbon (BC) and their association with cardiovascular disease (CVD) risk factors, arterial endothelial function, incident CVD events, and all-cause mortality. Approach and Results— Data from the HeartSCORE study (Heart Strategies Concentrating on Risk Evaluation) were used to estimate 1-year average air pollution exposure to PM2.5 and BC using land use regression models. Correlates of PM2.5 and BC were assessed using linear regression models. Associations with clinical outcomes were determined using Cox proportional hazards models, adjusting for traditional CVD risk factors. Data were available on 1717 participants (66% women; 45% blacks; 59±8 years). Blacks had significantly higher exposure to PM2.5 (mean 16.1±0.75 versus 15.7±0.73µg/m3; P=0.001) and BC (1.19±0.11 versus 1.16±0.13abs; P=0.001) compared with whites. Exposure to PM2.5, but not BC, was independently associated with higher blood glucose and worse arterial endothelial function. PM2.5 was associated with a higher risk of incident CVD events and all-cause mortality combined for median follow-up of 8.3 years. Blacks had 1.45 (95% CI, 1.00–2.09) higher risk of combined CVD events and all-cause mortality than whites in models adjusted for relevant covariates. This association was modestly attenuated with adjustment for PM2.5. Conclusions— PM2.5 exposure was associated with elevated blood glucose, worse endothelial function, and incident CVD events and all-cause mortality. Blacks had a higher rate of incident CVD events and all-cause mortality than whites that was only partly explained by higher exposure to PM2.5.

Comparison of long-term safety and efficacy outcomes after drug-eluting and bare-metal stent use across racial groups: Insights from NHLBI Dynamic Registry☆

BACKGROUND Long-term data on outcomes after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) and bare-metal stent (BMS) across racial groups are limited, and minorities are under-represented in existing clinical trials. Whether DES has better long-term clinical outcomes compared to BMS across racial groups remains to be established. Accordingly, we assessed whether longer-term clinical outcomes are better with DES compared to BMS across racial groups. METHODS Using the multicenter National Heart, Lung, and Blood Institute (NHLBI)-sponsored Dynamic Registry, 2-year safety (death, MI) and efficacy (repeat revascularization) outcomes of 3326 patients who underwent PCI with DES versus BMS were evaluated. RESULTS With propensity-score adjusted analysis, the use of DES, compared to BMS, was associated with a lower risk for death or MI at 2 years for both blacks (adjusted Hazard Ratio (aHR)=0.41, 95% CI 0.25-0.69, p<0.001) and whites (aHR=0.67, 95% CI 0.51-0.90, p=0.007). DES use was associated with a significant 24% lower risk of repeat revascularization in whites (aHR=0.76, 95% CI 0.60-0.97, p=0.03) and with nominal 34% lower risk in blacks (aHR=0.66, 95% CI 0.39-1.13, p=0.13). CONCLUSION The use of DES in PCI was associated with better long-term safety outcomes across racial groups. Compared to BMS, DES was more effective in reducing repeat revascularization in whites and blacks, but this benefit was attenuated after statistical adjustment in blacks. These findings indicate that DES is superior to BMS in all patients regardless of race. Further studies are needed to determine long-term outcomes across racial groups with newer generation stents.

Association of beta-blocker use with increased aortic wave reflection

Studies have found less cardiovascular risk reduction in patients treated with beta-blockers (BBs) compared with other agents. We compared the severity of aortic atherosclerosis, arterial stiffness, and wave reflection in patients treated and not treated with BBs. Seventy-two patients, 37 treated with BBs and 35 not treated, referred for transesophageal echocardiography were studied. Augmentation index (AI), heart-rate-corrected AI (AI-75), aortic systolic (SBP) and diastolic blood pressure, pulse wave velocity (PWV), and aortic intima-media thickness (MAIMT) were measured. There were no differences in MAIMT (2.8 +/- 1.6 mm vs. 2.4 +/- 1.2 mm, P = .20) and PWV (8.9 +/- 2.0 m/s vs. 8.5 +/- 2.6 m/s, P = .46) between the BB and non-BB groups. The BB group had higher AI (28.7 +/-11.9% vs. 22.3 +/- 14.1%, P = .04), AI-75 (27.7 +/- 10.7% vs. 20.1+/- 11.0%, P = .005), aortic SBP (140 +/- 21 mm Hg vs. 125 +/- 21 mm Hg, P = .01), and aortic pulse pressure (62 +/- 20 mm Hg vs. 47 +/- 19 mm Hg, P = .01) than the non-BB group despite similar brachial blood pressure. BB use was associated with increased aortic wave reflection despite similar degree of aortic atherosclerosis.