Muaz M. Abudiab

Cardiac output response to exercise in relation to metabolic demand in heart failure with preserved ejection fraction

Exercise intolerance is a hallmark of heart failure with preserved ejection fraction (HFpEF), yet its mechanisms remain unclear. The current study sought to determine whether increases in cardiac output (CO) during exercise are appropriately matched to metabolic demands in HFpEF.

Quadricuspid Aortic Valve Characteristics, Associated Structural Cardiovascular Abnormalities, and Clinical Outcomes

Background— Quadricuspid aortic valve (QAV) is a rare congenital cardiac defect. This study sought to determine QAV frequency in a large echocardiography database, to characterize associated cardiovascular abnormalities, and to describe long-term outcomes. Methods and Results— Fifty patients (mean±SD age, 43.5±21.8 years at the time of the index diagnosis; female sex, 52%) received a diagnosis of QAV between January 1, 1975, and March 14, 2014 (frequency, 0.006%). The QAV was type A in 32% and type B in 32% (Hurwitz and Roberts classification). Aortic dilatation was present in 29% of the patients, and 26% had moderate or severe aortic valve regurgitation at the index diagnosis. Stenosis affected only 8% of the valves and was mild. Other findings, including abnormalities of other cardiac valves, septal defects, persistent left superior vena cava, and patent ductus arteriosus, were present in 32% of patients. During a mean±SD follow-up of 4.8±5.6 years, 8 patients underwent aortic valve surgery, with severe aortic valve regurgitation being the surgical indication in 7 patients. One patient with mild to moderate aortic valve regurgitation underwent aortic valve repair for obstruction of the left coronary ostium by the accessory cusp of QAV. No infective endocarditis or aortic dissection was found. Overall survival was 91.5% and 87.7% at 5 and 10 years. Conclusions— Aortic dilatation and other structural cardiac abnormalities were relatively common among patients with QAV. Aortic valve regurgitation was the predominant hemodynamic abnormality and the indication for aortic valve surgery in most patients who received surgery. Long-term survival was excellent.

Differentiating scleroderma renal crisis from other causes of thrombotic microangiopathy in a postpartum patient

Thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS), and scleroderma renal crisis (SRC) all present with features of thrombotic microangiopathy. Distinguishing among these entities is critical, however, as treatments differ and may be mutually exclusive. We describe the case of a 25-year-old woman with an undefined mixed connective tissue disease who presented 6 weeks post-partum with fever, transient aphasia, thrombocytopenia, hemolytic anemia, and acute kidney injury eventually requiring initiation of hemodialysis. Renal biopsy revealed thrombotic microangiopathy. Renal function did not improve despite immediate initiation of plasma exchange, and an angiotensin-converting enzyme (ACE) inhibitor was initiated following discontinuation of plasma exchange. At last follow up, she remained dialysis dependent. Due to the myriad causes of thrombotic microangiopathy and potential for diagnostic uncertainty, the patient’s response to therapy should be closely monitored and used to guide modification of therapy.

Use of Functional Aerobic Capacity Based on Stress Testing to Predict Outcomes in Normal, Overweight, and Obese Patients

OBJECTIVE To determine the poorly studied relationship between functional aerobic capacity (FAC) as measured by treadmill stress testing and mortality in normal, overweight, and obese patients. PATIENTS AND METHODS Patients were identified retrospectively from the stress testing database at Mayo Clinic in Rochester, Minnesota. We selected 5328 male nonsmokers (mean ± SD age, 51.8±11.5 years) without baseline cardiovascular disease who were referred for treadmill exercise testing between January 1, 1986, and December 31, 1991, and classified them by body mass index (BMI) into normal-weight (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (≥30 kg/m(2)) categories. Functional aerobic capacity was assessed by maximal exercise test results based on age- and sex-specific metabolic equivalents, and patients were stratified into fitness quintiles. Cox proportional hazards analysis was used to determine the relationship of all-cause mortality to fitness in each BMI category. RESULTS There were 322 deaths during 14 years of follow-up. After adjustment for age and exercise confounders, FAC predicted mortality in the 3 BMI groups. Hazard ratios for FAC less than 80% of predicted vs a reference group with normal BMI and fitness (FAC ≥100%) were 1.754 (95% CI, 0.874-3.522), 1.962 (1.356-2.837), and 1.518 (1.056-2.182) for the normal, overweight, and obese groups, respectively. The CIs of the hazard ratios overlapped with no statistically significant differences (P>.05). CONCLUSION A significant increase in mortality occurs with FAC below 80% of predicted for overweight and obese subjects and below 70% for normal weight subjects. Our results suggest that clinicians need not adjust the standard for low fitness in obese patients.

Paradoxical coronary artery embolism - A rare cause of myocardial infarction

Paradoxical coronary artery embolism is a rare, but often an underdiagnosed cause of acute myocardial infarction. It should be considered in patient who presents with chest pain and otherwise having a low risk profile for atherosclerosis coronary artery disease. We describe a case of paradoxical coronary artery embolism causing ST segment elevation myocardial infarction in a patient with upper extremity venous thrombosis. Echocardiography demonstrated a patent foramen ovale (PFO) with bidirectional shunt. In addition to treatment of acute coronary event closure of the PFO should be considered to prevent a recurrence.

Quantitation of valve regurgitation severity by three-dimensional vena contracta area is superior to flow convergence method of quantitation on transesophageal echocardiography

Quantitation of regurgitation severity using the proximal isovelocity acceleration (PISA) method to calculate effective regurgitant orifice (ERO) area has limitations. Measurement of three‐dimensional (3D) vena contracta area (VCA) accurately grades mitral regurgitation (MR) severity on transthoracic echocardiography (TTE).

Inpatient Cardiology Consultation: Lessons Learned During Fellowship.

Inpatient consultation in the academic setting can be an exasperating experience for the cardiology trainee. Perception of unnecessary consultation, suboptimal triaging of calls on the basis of acuity, and variable interactions with requesting services and providers are some of the challenges

Mean Right Atrial Pressure for Estimation of Left Ventricular Filling Pressure in Patients with Normal Left Ventricular Ejection Fraction: Invasive and Noninvasive Validation

Background: There is a paucity of data on the utility of right atrial pressure (RAP) for estimating pulmonary capillary wedge pressure (PCWP) in patients with normal ejection fraction (EF), including patients with heart failure with preserved EF. Methods: Mean RAP was compared with PCWP in 129 patients (mean age, 61 ± 11 years; 45% men) with exertional dyspnea enrolled in a multicenter study. Measurements included left ventricular volumes, EF, and mitral inflow velocities. Results: Mean PCWP was 14 ± 7 mm Hg, and mean RAP was 8 ± 5 mm Hg. A significant relation was present between mean RAP and mean PCWP (r2 = 0.5, P < .001). RAP > 8 mm Hg had 76% sensitivity and 86% specificity in detecting mean PCWP > 12 mm Hg. In 101 patients with inconclusive mitral filling pattern (defined according to American Society of Echocardiography/European Association of Cardiovascular Imaging 2016 diastolic function recommendations), RAP by catheterization had sensitivity of 73% and specificity of 91%. In a subset of 59 patients with echocardiographic assessment of mean RAP, RAP by echocardiography had sensitivity of 76% and specificity of 89%. Conclusions: Mean RAP provides useful information about mean PCWP in many patients with normal left ventricular EF. There is good sensitivity and excellent specificity when combining invasive or noninvasive RAP and mitral velocities to determine if PCWP is elevated. HighlightsMean RAP provides useful information about mean PCWP in patients with normal LV EF.RAP may be used to draw conclusions about PCWP if one of three variables is missing.RAP may be an inaccurate measure of PCWP with predominant RV disease, severe TR, or MR.

Role of transesophageal echocardiography in the diagnosis of paradoxical low flow, low gradient severe aortic stenosis

Background and Objectives Prior studies indicate that up to 35% of cases of severe aortic stenosis (AS) have paradoxical low flow, low gradient despite preserved left ventricular ejection fraction (LVEF). However, error in left ventricular outflow tract (LVOT) diameter may lead to misclassification. Herein, we determined whether measurement of LVOT diameter by transesophageal echocardiography (TEE) results in reclassification of cases to non-severe AS. Subjects and Methods Patients with severe AS with aortic valve area (AVA) <1 cm2 by transthoracic echocardiography (TTE) within 6 months were studied. Paradoxical low flow, low gradient was defined as mean Doppler gradient (MG) <40 mm Hg and stroke volume index (SVI) ≤35 mL/m2. Preserved LVEF was defined as ≥0.50. Results Among 108 patients, 12 (15%) had paradoxical low flow, low gradient severe AS despite preserved LVEF based on TTE measurement. When LVOT diameter by TEE in 2D was used, only 5 (6.3%) patients had low flow, low gradient severe AS (p<0.001). Coefficients of variability for intraobserver and interobserver measurement of LVOT were <10%. However, the limits of agreement between TTE and TEE measurement of LVOT ranged from 0.43 cm (95% confidence interval [CI]: 0.36 to 0.5) to -0.31 cm (95% CI: -0.38 to -0.23). Conclusion TEE measured LVOT diameter may result in reclassification to moderate AS in some patients due to low prevalence of true paradoxical low flow, low gradient (PLFLG) severe AS.

Anomalous coronary artery in a transplanted heart: a rare incidental diagnosis.

Coronary artery anomaly is a rare postoperative coronary angiographic finding in heart transplant recipients. We report a case of anomalous origin of the right coronary artery in an asymptomatic 70-year-old heart transplant patient. Most coronary artery anomalies are benign, but surgical treatment may be necessary in major coronary artery anomalies that are known to have adverse outcomes.