Accuracy of Echocardiographic Cardiac Index Assessment in Subjects with Preserved Left Ventricular Ejection Fraction.

INTRODUCTION: We aimed to determine the accuracy of the echocardiographic assessment of cardiac index (CI) in subjects with preserved left ventricular ejection fraction (LVEF). METHODS: Thirty-three subjects with LVEF >50%, normal sinus rhythm, and a broad spectrum of hemodynamic profiles underwent echocardiography immediately followed by right heart catheterization. As gold standards, CI was assessed using thermodilution [CI (TD)] and the Fick method [CI (F)]. Echocardiographic CI was assessed by four methods: from the left ventricular outflow tract (LVOT) velocity time integral and the LVOT diameter as measured [CI (LVOTm)] as well as estimated from body surface area [CI (LVOTe)], and from stroke volume indices assessed using the biplane [CI (BP)] and monoplane [CI (MP)] methods. RESULTS: The mean CI (TD), CI (F), CI (LVOTm), CI (LVOTe), CI (BP), and CI (MP) were 3.0 ± 0.9, 3.1 ± 0.7, 2.8 ± 0.6, 3.3 ± 0.6, 2.0 ± 0.6, and 2.2 ± 0.7 L/min/m(2) . There were modest correlations between CI (TD) and CI (F) and all four noninvasive measures of CI with r(2) values ranging from 0.09 to 0.30. CI (LVOTm) underestimated CI (TD) and CI (F) by 0.3 and 0.3 L/min/m(2) , CI (LVOTe) overestimated CI (TD) and CI (F) by 0.3 and 0.2 L/min/m(2) , and CI (BP) and CI (MP) underestimated CI (TD) and CI (F) by 1.1 and 1.1 L/min/m(2) and 0.9 and 0.9 L/min/m(2) , respectively, with large limits of agreement for all comparisons. CONCLUSIONS: In subjects with nondilated left ventricles with preserved LVEF, flow- or volume-based measures of CI by 2D echocardiography may not accurately reflect CI (TD) and CI (F). Further larger studies are required to verify our findings and to evaluate the accuracy of contrast and 3D echocardiography in this setting.

Associations between surface markers on blood monocytes and carotid atherosclerosis in HIV-positive individuals.

Chronic HIV infection is associated with increased risk of cardiovascular disease (CVD), including in patients with virological suppression. Persistent innate immune activation may contribute to the development of CVD via activation of monocytes in these patients. We investigated whether changes in monocyte phenotype predict subclinical atherosclerosis in virologically suppressed HIV-positive individuals with low cardiovascular risk. We enroled 51 virologically suppressed HIV-positive individuals not receiving protease inhibitors or statins and 49 age-matched uninfected controls in this study. Carotid artery intima-media thickness (cIMT) was used as a surrogate marker for CVD, and traditional risk factors, including Framingham risk scores, were recorded. Markers of monocyte activation (CD14, CD16, CCR2, CX3CR1, CD38, HLA-DR and CD11b) were measured in whole-blood samples by flow cytometry. Associations were assessed using univariate and multivariate median regressions. Median cIMT was similar between HIV-positive and HIV-negative participants (P=0.3), although HIV-positive patients had significantly higher Framingham risk score (P=0.009) and systemic inflammation. Expression of two monocyte markers, CD11b and CX3CR1, independently predicted carotid artery thickness in HIV-positive individuals after controlling for Framingham risk score (P=0.025 and 0.015, respectively). These markers were not predictive of carotid artery thickening in controls. Our study indicates that monocyte surface markers may serve as novel predictors of CVD in HIV-positive individuals and is consistent with an important role for monocyte activation in the progression of HIV-related cardiovascular pathology.

Asymptomatic people with well-controlled HIV do not have abnormal left ventricular global longitudinal strain.

Background: Previous studies have reported impairment in systolic and diastolic function in people with HIV (PWHIV). Our aim was to determine if echocardiographically measured left ventricular (LV) global longitudinal strain (GLS) is abnormal in asymptomatic PWHIV. Methods: A cross-sectional study of PWHIV (n = 98, 89% male, median age 53 years) and HIV-negative people (n = 50, median age 53 years) without known cardiovascular disease were recruited from a single centre. All participants completed a health/lifestyle questionnaire, provided a fasting blood sample, and underwent a comprehensive echocardiogram for assessment of diastolic and systolic LV function, including measurement of GLS. Results: All PWHIV were receiving antiretroviral therapy (ART) for a median of 12 years (IQR: 6.9, 22.4), the majority with good virological control (87% suppressed) and without immunological compromise (median CD4 598 cells/µl, IQR: 388, 841). Compared with controls of similar age and gender, there was no difference in GLS [mean GLS -20.3% (SD 2.5%) vs. -21.0% (SD 2.5%), p = 0.14] or left ventricular ejection fractions [65.3% (SD 6.3) vs. 64.8% (SD 4.8), p = 0.62]. Following adjustment for covariates (gender, heart rate, systolic and diastolic blood pressure, and fasting glucose), the difference in GLS remained non-significant. There were no differences in LV diastolic function between the groups. Exposure to at least one mitochondrially toxic ART drug (didanosine, stavudine, zidovudine, or zalcitabine) was not associated with impairment of LV systolic function. Conclusion: No clinically significant impairment of myocardial systolic function, as measured by LV GLS, was detected in this predominantly Caucasian male population of PWHIV on long-term ART, with no history of cardiovascular disease.

Vascular Responses Among Adults Four Years Post Exposure to 6 Weeks of Smoke from the Hazelwood Coal Mine Fire.

Background and Aims: Mega-wild fires are exposing large communities to weeks or months of high concentration smoke-related fine particulate air pollution (PM). However, little research has examined the long-term vascular responses from exposure to PM of this concentration and duration. We investigated whether level of exposure to 6 weeks of PM from the 2014 Hazelwood coal mine fire was associated with abnormal vascular responses approximately four years later. Methods: A cross-sectional analysis was undertaken of 387 participants (225 exposed, 162 unexposed) aged 55-89 years, 3.5-4 years after the mine fire. The primary outcome was flow-mediated dilatation (FMD), with time to reach peak diameter as the secondary outcome. Other secondary markers included high-sensitivity C-reactive protein (hsCRP) and ischaemic Electrocardiogram (ECG) changes. Results: There was no evidence of a difference in FMD between participants with high, medium, low or no mine-fire related PM2.5 exposure (4.09% vs 4.06% vs 4.02% vs 3.98%, respectively, p=0.99). Likewise, there was no difference in hsCRP or ischaemic ECG changes. In contrast, there was evidence of a difference in time to peak diameter (p=0.002) with more unexposed participants reaching peak diameter within 30 seconds (36%) compared to those who had high, medium, or low exposure (23%, 22%, 13%, respectively). Multivariate ordinal logistic regression analysis suggested that township, Morwell (exposed) vs Sale (unexposed), but not level of PM2.5 exposure, was associated with delayed time to peak diameter (OR 2.71; 95% CI 1.56, 4.69). Smokers also had delayed time to peak diameter. Conclusion: There was no association between level of exposure to PM2.5 from the 6-week Hazelwood coal mine fire smoke event and reduced FMD, elevated hsCRP or ischaemic ECG four years later. Evidence of delayed time to peak diameter observed in adults from the exposed town, compared to an unexposed town, requires further investigation.

Accuracy of Doppler echocardiography to estimate key hemodynamic variables in subjects with normal left ventricular ejection fraction.

BACKGROUND: The accuracy of Doppler echocardiography to estimate key hemodynamic parameters in subjects with normal left ventricular ejection fraction (LVEF) has not been fully investigated. METHODS AND RESULTS: Thirty-six subjects with LVEF >50% (median age 62 years), with a broad clinical profile, underwent Doppler echocardiography immediately followed by right heart catheterization. Correlation coefficients between invasive and noninvasive right atrial pressure (RAP), systolic (sPAP) and mean (mPAP) pulmonary artery pressure, cardiac output (CO), and pulmonary vascular resistance (PVR) were 0.39, 0.70, 0.72, 0.57, and 0.60 (P < .001 for all). There was no significant correlation between invasive and noninvasive (based on the peak early transmitral to peak early septal mitral annular velocity ratio) pulmonary capillary wedge pressure (PCWP; r = 0.23; P = .18). Bland-Altman plots revealed variable bias but with consistently large limits of agreement for all noninvasive parameters, particularly PCWP. Areas under the receiver operating characteristic curve for noninvasive sPAP, CO, PVR, and PCWP to predict an invasively assessed mPAP ≥25 mm Hg, cardiac index <2.5 L min(-1) m(-2), PVR >3 Wood units, and PCWP ≤15 mm Hg, respectively, were 0.92, 0.83, 0.70, and 0.58. CONCLUSIONS: Single Doppler echocardiography parameters are not accurate enough to reliably estimate key hemodynamic parameters, particularly PCWP, in subjects with normal LVEF.

Impact of rosuvastatin on atherosclerosis in people with HIV at moderate cardiovascular risk: a randomised, controlled trial.

BACKGROUND: People living with HIV-1 (PLHIV) are at increased risk for cardiovascular disease. OBJECTIVE: This study aimed to determine if PLHIV would benefit from starting statins at a lower threshold than currently recommended in the general population. DESIGN: A double-blind multicentre, randomised, placebo-controlled trial was performed. METHODS: Participants (n = 88) with well controlled HIV, at moderate cardiovascular risk (Framingham score of 10-15%), and not recommended for statins were recruited from Australia and Switzerland. They were randomized 1 : 1 to rosuvastatin (n = 44) 20 mg daily, 10 mg if co-administered with ritonavir/cobicistat-boosted antiretroviral therapy, or placebo (n = 40) for 96 weeks. Assessments including fasting blood collection and carotid--intima media thickness (CIMT) were performed at baseline, and weeks 48 and 96. The primary outcome was the change from baseline to week 96 in CIMT (clinicaltrials.gov: NCT01813357). RESULTS: Participants were predominantly men [82 (97.6%); mean age 54 years (SD 6.0)]. At 96 weeks, there was no difference in the progression of CIMT between the rosuvastatin (mean 0.004 mm, SE 0.0036) and placebo (0.0062 mm, SE 0.0039) arms (P = 0.684), leading to no difference in CIMT levels between groups at week 96 [rosuvastatin arm, 0.7232 mm (SE 0.030); placebo arm 0.7785 mm (SE 0.032), P = 0.075].Adverse events were common (n = 146) and predominantly in the rosuvastatin arm [108 (73.9%)]. Participants on rosuvastatin were more likely to cease study medication because of an adverse event [7 (15.9%) vs. 2 (5.0%), P = 0.011]. CONCLUSION: In PLHIV, statins prescribed at a lower threshold than guidelines did not lead to improvements in CIMT but was associated with significant adverse events.

Markers of Cardiovascular Disease among Adults Exposed to Smoke from the Hazelwood Coal Mine Fire.

Little research has examined the effects of high concentration, medium-duration smoke exposure on cardiovascular health. We investigated whether six weeks of exposure to smoke from the 2014 Hazelwood coal mine fire in Victoria (Australia), was associated with long-term clinical or subclinical cardiovascular disease approximately four years later, in adult residents of the towns of Morwell (exposed, n = 336) and Sale (unexposed, n = 162). The primary outcome was serum high sensitivity (hs) C-reactive protein (CRP). Blood pressure, electrocardiogram, flow mediated dilatation and serum levels of hs-troponin, N-terminal pro B-type natriuretic peptide and lipids were secondary outcomes. There was no significant difference in weighted median hsCRP levels between exposed and unexposed participants (1.9 mg/L vs. 1.6 mg/L, p = 0.273). Other outcomes were comparable between the groups. hsCRP was associated in a predictable manner with current smoking, obesity and use of lipid-lowering therapy. Four years after a 6-week coal mine fire, this study found no association between smoke exposure and markers of clinical or subclinical cardiovascular disease in exposed adults.

Large-artery stiffness contributes to the greater prevalence of systolic hypertension in elderly women.

OBJECTIVES: To determine whether sex differences in large-artery stiffness contribute to the greater prevalence of systolic hypertension in elderly women than in elderly men. DESIGN: During a single visit arterial stiffness was assessed in the unmedicated state using four parameters. PARTICIPANTS: Three hundred seventy-four women with a mean age+/-standard deviation of 72+/-5 and 296 men aged 71+/-5 participated. SETTING: Hypertensive patients were recruited from general practice as part of the second Australian National Blood Pressure Study in Melbourne, Australia. MEASUREMENTS: Large-artery stiffness was assessed using multiple methodologies, including aortic arch stiffness (beta-index) using M-mode ultrasound and arterial compliance and augmentation index using noninvasive carotid pressure and aortic flow measurements. RESULTS: Women had greater carotid and brachial pulse pressure (PP) than men (P<.001), despite higher mean arterial pressure in men. Mean arterial compliance was lower in women (0.20+/-0.12 vs 0.28+/-0.16 mL/mmHg, P<.001) even after correction for aortic area, and aortic arch stiffness was higher (30+/-36 vs 23+/-22; P<.01). Consistent with both a stiffer proximal circulation and a shorter distance to reflection sites, women had higher augmentation index (38+/-11% vs 29+/-12%, P<.001). In multivariate analysis, sex was an independent determinant of all arterial stiffness indices. CONCLUSION: Independently of known confounders, elderly hypertensive women have stiffer large arteries, greater central wave reflection, and higher PP than elderly men. Stiffer large arteries likely contribute to the greater prevalence of systolic hypertension in elderly women and may partly explain the acceleration in postmenopausal cerebrovascular and cardiac complications.