Simonette T Sawit

Right ventriculo-arterial coupling in pulmonary hypertension: a magnetic resonance study

Objective To quantify right ventriculo-arterial coupling in pulmonary hypertension by combining standard right heart catheterisation (RHC) and cardiac magnetic resonance (CMR) and to estimate it non-invasively with CMR alone. Design Cross-sectional analysis in a retrospective cohort of consecutive patients. Setting Tertiary care centre. Patients 139 adults referred for pulmonary hypertension evaluation. Interventions CMR and RHC within 2 days (n=151 test pairs). Main outcome measures Right ventriculo-arterial coupling was quantified as the ratio of pulmonary artery (PA) effective elastance (Ea, index of arterial load) to right ventricular maximal end-systolic elastance (Emax, index of contractility). Right ventricular end-systolic volume (ESV) and stroke volume (SV) were obtained from CMR and adjusted to body surface area. RHC provided mean PA pressure (mPAP) as a surrogate of right ventricular end-systolic pressure, pulmonary capillary wedge pressure (PCWP) and pulmonary vascular resistance index (PVRI). Ea was calculated as (mPAP − PCWP)/SV and Emax as mPAP/ESV. Results Ea increased linearly with advancing severity as defined by PVRI quartiles (0.19, 0.50, 0.93 and 1.63 mm Hg/ml/m2, respectively; p<0.001 for trend) whereas Emax increased initially and subsequently tended to decrease (0.52, 0.67, 0.54 and 0.56 mm Hg/ml/m2; p=0.7). Ea/Emax was maintained early but increased markedly with severe hypertension (0.35, 0.72, 1.76 and 2.85; p<0.001), indicating uncoupling. Ea/Emax approximated non-invasively with CMR as ESV/SV was 0.75, 1.17, 2.28 and 3.51, respectively (p<0.001). Conclusions Right ventriculo-arterial coupling in pulmonary hypertension can be studied with standard RHC and CMR. Arterial load increases with disease severity whereas contractility cannot progress in parallel, leading to severe uncoupling.

Non-invasive estimation of pulmonary vascular resistance with cardiac magnetic resonance

AIM To develop a cardiac magnetic resonance (CMR) method for non-invasive estimation of pulmonary vascular resistance (PVR). METHODS AND RESULTS The study comprised 100 consecutive patients with known or suspected pulmonary hypertension (PH; 53 ± 16 years, 73% women) who underwent same-day right heart catheterization (RHC) and CMR. Increased PVR was defined from RHC as >3 WU (n = 66, 66%). From CMR cine and phase-contrast images, right ventricular (RV) volumes and ejection fraction (RVEF), pulmonary artery (PA) flow velocities and areas, and cardiac output were quantified. The best statistical model to estimate PVR was obtained from a derivation cohort (n = 80) based on physiological plausibility and statistical criteria. Validity of the model was assessed in the remaining 20 patients (validation cohort). The CMR-derived model was: estimated PVR (in WU) = 19.38 - [4.62 × Ln PA average velocity (in cm/s)] - [0.08 × RVEF (in %)]. In the validation cohort, the correlation between invasively quantified and CMR-estimated PVR was 0.84 (P < 0.001). The mean bias between the RHC-derived and CMR-estimated PVR was -0.54 (agreement interval -6.02 to 4.94 WU). The CMR model correctly classified 18 (90%) of patients as having normal or increased PVR (area under the receiver operator characteristics curve 0.97; 95% confidence interval: 0.89-1.00). CONCLUSIONS Non-invasive estimation of PVR using CMR is feasible and may be valuable for PH diagnosis and/or follow-up.

Diagnostic value of coronary artery calcium scoring in low-intermediate risk patients evaluated in the emergency department for acute coronary syndrome.

Early and accurate triage of patients with possible ischemic chest pain remains challenging in the emergency department because current risk stratification techniques have significant cost and limited availability. The aim of this study was to determine the diagnostic value of the coronary artery calcium score (CACS) for the detection of obstructive coronary artery disease (CAD) in low- to intermediate-risk patients evaluated in the emergency department for suspected acute coronary syndromes. A total of 225 patients presenting to the emergency department with acute chest pain and Thrombolysis In Myocardial Infarction (TIMI) scores <4 who underwent non-contrast- and contrast-enhanced coronary computed tomographic angiography were included. CACS was calculated from the noncontrast scan using the Agatston method. The prevalence of obstructive CAD (defined from the contrast scan as ≥ 50% maximal reduction in luminal diameter in any segment) was 9% and increased significantly with higher scores (p <0.01 for trend). CACS of 0 were observed in 133 patients (59%), of whom only 2 (1.5%) had obstructive CAD. The diagnostic accuracy of CACS to detect obstructive CAD was good, with an area under the receiver-operating characteristic curve of 0.88 and a negative predictive value of 99% for a CACS of 0. In a multivariate model, CACS was independently associated with obstructive CAD (odds ratio 7.01, p = 0.02) and provided additional diagnostic value over traditional CAD risk factors. In conclusion, CACS appears to be an effective initial tool for risk stratification of low- to intermediate-risk patients with possible acute coronary syndromes, on the basis of its high negative predictive value and additive diagnostic value.

Usefulness of Cardiac Computed Tomographic Delayed Contrast Enhancement of the Left Atrial Appendage Before Pulmonary Vein Ablation

Left atrial appendage (LAA) contrast filling defects are commonly found in patients undergoing multidetector cardiac computed tomography (CCT) before catheter ablation of atrial fibrillation. Delayed CCT allows quantification of the LAA delayed/initial attenuation ratio and improves accuracy for LAA thrombus detection, which may obviate routine transesophageal echocardiography (TEE) before ablation. CCT with contrast-enhanced scans (initial CCT) and with noncontrast-enhanced scans (delayed CCT) was performed in 176 patients. LAA was evaluated for filling defects. LAA apex, left atrial (LA) body, and ascending aorta (AA) attenuations (Hounsfield units) were measured on initial and delayed cardiac computed tomograms to calculate LAA, LA, LAA/LA, and LAA/AA attenuation ratios. LAA, initial LAA/LA, and initial LAA/AA attenuation ratios differed significantly in patients with versus without filling defects on cardiac computed tomogram, those with atrial fibrillation versus normal sinus rhythm, and those with abnormal left ventricular ejection fraction versus larger LA volumes (p <0.05). In 70 patients (40%) who underwent TEE, 13 LAA filling defects were seen on initial cardiac computed tomogram. Two defects persisted on delayed cardiac computed tomogram and thrombus was confirmed on transesophageal echocardiogram. Sensitivity, specificity, and positive and negative predictive values of initial CCT for LAA thrombi detection were 100%, 84%, 15%, and 100%, respectively. With delayed CCT these values increased to 100%. Intraobserver and interobserver reproducibilities for cardiac computed tomographic measurements were good (intraclass correlation 0.72 to 0.97, kappa coefficients 0.93 to 1.00). In conclusion, delayed CCT provided an increase in diagnostic accuracy of CCT for detection of LAA thrombus in patients with atrial fibrillation before ablation, which may decrease the need for routine TEE before the procedure.

Evaluation of right ventricular function and post-operative findings using cardiac computed tomography in patients with left ventricular assist devices

BACKGROUND Right ventricular (RV) failure is a major contributor to morbidity and mortality after left ventricular assist device (LVAD) implantation. Accurate evaluation of RV function in patients with LVAD remains challenging. We hypothesized that, after LVAD implantation, electrocardiographic-gated cardiac computed tomography (CCT) allows RV evaluation with higher feasibility and reproducibility compared with echocardiography. METHODS Thirty-six patients with an implanted LVAD who had 2-dimensional echocardiography and CCT evaluation were studied. RV end-diastolic and end-systolic volumes and ejection fraction were quantified using CCT. RV fractional area change, tricuspid annular plane systolic excursion and RV end-diastolic short-to-long axis ratio were calculated by echocardiography. Intraclass correlation coefficients (ICCs) and Bland-Altman analysis were used to assess intra- and interobserver reproducibility for all measurements. RESULTS The quality of CCT studies was good in all cases except for one. Intra- and interobserver reproducibility for all CCT measurements was high (interobserver ICC for RV ejection fraction = 0.89, 95% confidence interval 0.74 to 0.95). Echocardiographic indices of RV function and geometry had lower reproducibility. The echocardiographic index that best correlated with the CCT-determined RV ejection fraction was RV fractional area change (r = 0.80, p < 0.001). In addition, CCT detected relevant post-operative findings in 50% of the patients. CONCLUSIONS CCT is highly effective and reproducible compared with echocardiography for the evaluation of RV function in patients with LVAD support and provides relevant information on post-operative findings. Our results suggest that CCT should be considered as a useful imaging modality in this clinical setting.

The prevalence of metabolic syndrome among law enforcement officers who responded to the 9/11 World Trade Center attacks

BACKGROUND Law enforcement officers (LEOs) experience high rates of cardiovascular events compared with the general US population. Metabolic syndrome (MetS) confers an increased risk of cardiovascular disease and all-cause mortality. Data regarding MetS among LEOs are limited. METHODS We sought to determine the prevalence of MetS and its associated risk factors as well as gender differences among LEOs who participated in the World Trade Center (WTC) Law Enforcement Cardiovascular Screening (LECS) Program from 2008 to 2010. We evaluated a total of 2,497 participants, 40 years and older, who responded to the 9/11 WTC attacks. RESULTS The prevalence of MetS was 27%, with abdominal obesity and hypertension being the most frequently occurring risk factors. MetS and its risk factors were significantly higher among male compared to female LEOs, except for reduced HDL-cholesterol levels. CONCLUSIONS MetS is a rising epidemic in the United States, and importantly, approximately one in four LEOs who worked at the WTC site after 9/11 are affected. Am. J. Ind. Med. 59:752-760, 2016.

1381 LOW SERUM TESTOSTERONE IS ASSOCIATED WITH OBSTRUCTIVE SLEEP APNEA IN MIDDLE AGED MEN

reported into a volunteer, post-market registry, from July 14, 2000 to Sept 30, 2011 were reviewed and compared with infections reported in the product evaluation database. The advanced Titan includes hydrophilic coating across all components allowing for the absorption of an aqueous solution, while no components of the Alpha 1 employed a hydrophilic coating. Data was analyzed using a Pearson’s chi-square test to determine significance of reduction in reported infection between the Alpha IPP and the hydrophilic-coated Titan IPP. RESULTS: A total of 7031 implants and 322 infections (4.6%) were reported with the Alpha 1 implant, and 29,360 implants with 402 infections (1.4%) reported with the Titan implant, showing a statistically significant (p-value 0.0001) decrease in reported infections between the Alpha IPP and hydrophilic-coated Titan IPP. CONCLUSIONS: New advances in technology continue to improve efficacy and decrease adverse events for patients with severe ED treated with penile implants. Significant decreases in reported infection rates between the non-coated Alpha 1 IPP and the hydrophilic-coated Titan IPP suggest that the technology may contribute to decreased infections.

Evaluation of right ventriculoarterial coupling in pulmonary hypertension: a magnetic resonance study

Inadequate right ventriculo-arterial coupling is an important determinant of heart failure in pulmonary hypertension, in turn the main determinant of outcome in this disease. Coupling can be quantified as the ratio of pulmonary artery effective elastance (Ea, an index of arterial load) to right ventricular maximal end-systolic elastance (Emax, an index of contractility).