Clinical and echocardiographic features of aorto-atrial fistulas

Aorto-atrial fistulas (AAF) are rare but important pathophysiologic conditions of the aorta and have varied presentations such as acute pulmonary edema, chronic heart failure and incidental detection of the fistula. A variety of mechanisms such as aortic dissection, endocarditis with pseudoaneurysm formation, post surgical scenarios or trauma may precipitate the fistula formation. With increasing survival of patients, particularly following complex aortic reconstructive surgeries and redo valve surgeries, recognition of this complication, its clinical features and echocardiographic diagnosis is important. Since physical exam in this condition may be misleading, echocardiography serves as the cornerstone for diagnosis. The case below illustrates aorto-left atrial fistula formation following redo aortic valve surgery with slowly progressive symptoms of heart failure. A brief review of the existing literature of this entity is presented including emphasis on echocardiographic diagnosis and treatment

The EXERRT Trial: EXErcise to Regadenoson in Recovery Trial : a Phase 3b, Open-label, Parallel Group, Randomized, Multicenter Study to Assess Regadenoson Administration Following an Inadequate Exercise Stress Test as Compared to Regadenoson Without Exercise for Myocardial Perfusion Imaging Using a SPECT Protocol

BACKGROUND: This study assessed the non-inferiority and safety of regadenoson administration during recovery from inadequate exercise compared with administration without exercise. METHODS: Patients unable to achieve adequate exercise stress were randomized to regadenoson 0.4 mg either during recovery (Ex-Reg) or 1 hour after inadequate exercise (Regadenoson) (MPI1). All patients also underwent non-exercise regadenoson MPI 1-14 days later (MPI2). The number of segments with reversible perfusion defects (RPDs) detected using single photon emission computerized tomography imaging was categorized. The primary analysis evaluated the majority agreement rate between Ex-Reg and Regadenoson groups. RESULTS: 1,147 patients were randomized. The lower bound of the 95% confidence interval of the difference in agreement rates (-6%) was above the -7.5% non-inferiority margin, demonstrating non-inferiority of Ex-Reg to Regadenoson. Adverse events were numerically less with Ex-Reg (MPI1). In the Ex-Reg group, one patient developed an acute coronary syndrome and another had a myocardial infarction following regadenoson after exercise. Upon review, both had electrocardiographic changes consistent with ischemia prior to regadenoson. CONCLUSIONS: Administering regadenoson during recovery from inadequate exercise results in comparable categorization of segments with RPDs and with careful monitoring appears to be well tolerated in patients without signs/symptoms of ischemia during exercise and recovery

Simplified risk stratification criteria for identification of patients with MRSA bacteremia at low risk of infective endocarditis: implications for avoiding routine transesophageal echocardiography in MRSA bacteremia

The aim of this study was to identify patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia with low risk of infective endocarditis (IE) who might not require routine trans-esophageal echocardiography (TEE). We retrospectively evaluated 398 patients presenting with MRSA bacteremia for the presence of the following clinical criteria: intravenous drug abuse (IVDA), long-term catheter, prolonged bacteremia, intra-cardiac device, prosthetic valve, hemodialysis dependency, vertebral/nonvertebral osteomyelitis, cardio-structural abnormality. IE was diagnosed using the modified Duke criteria. Of 398 patients with MRSA bacteremia, 26.4 % of cases were community-acquired, 56.3 % were health-care-associated, and 17.3 % were hospital-acquired. Of the group, 44 patients had definite IE, 119 had possible IE, and 235 had a rejected diagnosis. Out of 398 patients, 231 were evaluated with transthoracic echocardiography (TTE) or TEE. All 44 patients with definite IE fulfilled at least one criterion (sensitivity 100 %). Finally, a receiver operator characteristic (ROC) curve was obtained to evaluate the total risk score of our proposed criteria as a predictor of the presence of IE, and this was compared to the ROC curve of a previously proposed criteria. The area under the ROC curve for our criteria was 0.710, while the area under the ROC curve for the criteria previously proposed was 0.537 (p < 0.001). The p-value for comparing those 2 areas was less than 0.001, indicating statistical significance. Patients with MRSA bacteremia without any of our proposed clinical criteria have very low risk of developing IE and may not require routine TEE

All that glitters is not gold; due diligence when interpreting pyrophosphate cardiac scans to avoid misdiagnosis of transthyretin cardiac amyloidosis.

Background Technetium-99m pyrophosphate (PYP) nuclear scan is currently considered the noninvasive test of choice for transthyretin cardiac amyloidosis (TTRCA) with a heart to lung ratio greater than 1.5 suggesting TTRCA. Case An 81 year old female presented to cardiology clinic for evaluation of previously diagnosed TTRCA. Her electrocardiogram (Figure 1A) showed bifasicular block and an echocardiogram (Figure 1B-D) demonstrated diffuse left ventricular hypertrophy. As part of the workup a PYP scan (Figure 1E) was performed and interpreted to have a planar ratio of 1.5 with Grade 2 Tc-99m pyrophosphate uptake, consistent with TTRCA. Decision-making While planar images appeared to show some cardiac uptake equal to that of bone in the contralateral thorax, review of the single-photon emission computed tomography (SPECT) images (Figure 1F) and blood pool reconstruction images (Figure 1G) demonstrated only bone uptake of the tracer, on a background of blood pool activity with no myocardial uptake. Subsequent testing revealed elevated free kappa light chains and the patient was referred to a hematologist for further evaluation. Conclusion Light chain amyloidosis should be first ruled out given implications for treatment. Furthermore, errors in diagnosis of TTRCA can occur when only planar images and ratio cutoffs are used. Due diligence to evaluate SPECT data to confirm myocardial Tc-99m PYP uptake is important to confirm the diagnosis of TTRCA

Impact of Pre-Existing Left Ventricular Dysfunction on Kidney Transplantation Outcomes: Implications for Patient Selection

Background. End-stage kidney disease patients with decreased left ventricular ejection fraction (EF) are often denied kidney transplantation (KT) for fear of poor graft and patient survival. Methods. We retrospectively studied all patients who underwent KT at our center between 2001 and 2005 to determine the impact of low EF on outcomes post KT. Low EF was defined as <50% EF by noninvasive cardiac imaging. Follow-up was for 1 year post KT. Outcomes assessed included hospitalization for congestive heart failure (CHF), cardiac events, and renal allograft and patient survival. Results. Among 254 patients, 37 had low EF (study group) and 217 had normal EF (>= 50%; control group). Post KT, the low EF group had a significantly higher rate of hospitalization for CHF. No significant difference was noted in the rate of cardiac events, graft loss, GFR, and all cause death at 12 months post KT. Conclusion. Patients with low EF should not be excluded from transplantation, given favorable outcomes