Clinical presentation and management of myocardial infarction with nonobstructive coronary arteries (MINOCA): A literature review.

Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA), as the name implies, is an acute myocardial infarction (MI) in the absence of significant coronary artery obstruction. Diagnosis and management of such cases have been challenging. There are many etiologies of MINOCA including coronary artery spasm, coronary microvascular dysfunction, plaque disruption, spontaneous coronary thrombosis or emboli, spontaneous coronary artery dissection, or cardiomyopathies. In this paper, the pathophysiology, diagnostic work-up, and clinical management for each subtype are described, and an overarching approach on how to evaluate and manage a patient presenting with MINOCA.

Myocardial viability assessment by PET: (82)Rb defect washout does not predict the results of metabolic-perfusion mismatch.

UNLABELLED: PET is a sensitive technique for the identification of viable myocardial tissue in patients with coronary disease. Metabolic assessment with (18)F-FDG is considered the gold standard for assessment of viability before surgical revascularization. Prior research has suggested that viability may be assessed with washout of (82)Rb between early and late resting images. Our objective was to determine whether assessment of myocardial viability with (82)Rb washout is reliable when compared with PET using (18)F-FDG. METHODS: We performed PET for 194 patients referred for PET (18)F-FDG/(82)Rb to assess viability for clinical indications. We included 151 patients with resting defects >10% of the left ventricle (LV) (n = 159 defects). Patients with smaller resting (82)Rb defects (<10% LV) were excluded for the purpose of this study. PET images acquired with (82)Rb and (18)F-FDG defined viability by the mismatch between metabolism and perfusion ((18)F-FDG >125% of (82)Rb uptake in the (82)Rb defect). Evidence of viability with (82)Rb was assessed by the presence of (i) severity: (82)Rb counts in the defect >50% of (82)Rb in the normal zone of the resting PET images; (ii) washout: decrease of (82)Rb counts in the defect from early to late resting (82)Rb images <17% between the first 90-s image and the final 300-s image; or (iii) combined severity and washout criteria, which required positive criteria for (i) and (ii) to indicate viability. RESULTS: Prevalence of viability by (18)F-FDG/(82)Rb criteria was 50% (n = 79). Severity criteria yielded a sensitivity of 76% and a specificity of 17%, washout criteria yielded a sensitivity of 81% and a specificity of 23%, and both criteria had a sensitivity of 63% and a specificity of 32%. Positive and negative predictive values were poor for all criteria. No correlation existed between (82)Rb washout and (18)F-FDG-(82)Rb mismatch (r(2) = 0.00). Multiple receiver-operating-characteristic plots showed very poor discrimination despite varying criteria for viability by (82)Rb (severity from 50% to 60% of normal zone, washout from 12% to 17%). CONCLUSION: (82)Rb washout from early to late resting images, combined with quantitative severity of the resting (82)Rb defect, did not yield results equivalent to PET (18)F-FDG-(82)Rb mismatch and may not accurately assess myocardial viability.

A comparison of HIV-positive patients with and without infective endocarditis: an echocardiographic study--the Emory Endocarditis Group experience.

OBJECTIVE: To determine the clinical features in HIV-positive patients with and without infective endocarditis (IE). PATIENTS AND METHODS: All bacteremic, HIV-positive patients with suspected IE admitted over a four-year period who underwent either transesophageal echocardiography (TEE) or transthoracic echocardiography (TTE) were retrospectively reviewed with regard to clinical, laboratory, and demographic characteristics. RESULTS: Ten (11.5%) of 87 HIV-positive patients had a clinical diagnosis of IE based on the Duke Criteria. The mean age of patients with IE was 37.8 years and without IE 39.9 years (P = NS). Both patient groups were similar with respect to gender, race, IVDA, renal failure requiring hemodialysis, history of predisposing heart disease, origin of infection, and causative organism of infection. The mean CD4 count (cells/microL) was 200.7 in patients with IE and 95.9 in patients without IE (P = NS). Of 10 HIV-positive patients with IE, seven had left-sided heart involvement, two had complications related to IE, three required cardiothoracic surgery, and three died. CONCLUSIONS: There were no differences found with regard to the clinical characteristics of HIV-positive patients with and without IE. No correlation could be drawn between mortality and the degree of immunosuppression in patients from this study. The high incidence of IE (11.5%) and mortality rate (30%) in this study suggests that IE in HIV-positive patients, including non-intravenous drug abusers, represents a real concern for clinicians and their management of these patients.

Staphylococcus aureus bacteremia and endocarditis: the Grady Memorial Hospital experience with methicillin-sensitive S aureus and methicillin-resistant S aureus bacteremia.

BACKGROUND: Staphylococcus aureus has become the leading cause of endocarditis in most published series, and nosocomial acquisition is becoming more frequent. Previous studies involved community acquired methicillin-sensitive S aureus (MSSA), but recently, methicillin-resistant S aureus(MRSA) infection has increased. This may reflect the growing presence of this microorganism in clinical practice. Few data exist comparing the relative rates of endocarditis with MSSA and MRSA bacteremia. The purpose of this study was to compare these rates in a bacteremic population referred for diagnostic echocardiography. METHODS: Since July 1999, the demographic and clinical information of 104 consecutive patients with at least 2 blood cultures with positive results for S aureus who were referred for echocardiography to be evaluated for endocarditis at Grady Memorial Hospital (Atlanta, Ga) have been entered into a database. This database has further been restricted to patients who have undergone either a transesophageal echocardiogram or a transthoracic echocardiogram. RESULTS: Of the 104 patients with S aureus bacteremia, 53 had an infection of MSSA and 51 had an infection of MRSA. There were 33 patients (31.7%) with echocardiographically confirmed endocarditis, 23 patients (43.4%) in the MSSA group versus 10 patients (19.6%) in the MRSA group (P <.009). Community-acquired MSSA bacteremia was the cause of most of the community-acquired S aureus endocarditis (20 patients [87%] vs 3 patients [30%], P =.004), and the nosocomial-acquired MRSA bacteremia was the cause of most of the nosocomial-acquired S aureus endocarditis (3 patients [13%] vs 7 patients [70%], P =.0001). CONCLUSION: Our study confirms that S aureus bacteremia is associated with high rates of endocarditis. MSSA bacteremia is associated with higher rates of endocarditis than MRSA. Community MSSA is the cause of most of the community endocarditis, whereas nosocomial MRSA is the cause of most of the MRSA endocarditis. Patients with S aureus bacteremia should be aggressively evaluated for endocarditis.