Mohammed Khan

Ventricular Fibrosis Suggested by Cardiovascular Magnetic Resonance in Adults With Repaired Tetralogy of Fallot and Its Relationship to Adverse Markers of Clinical Outcome

Background— Late morbidity and mortality remain problematic after repair of tetralogy of Fallot (TOF). We hypothesized that fibrosis detected by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) would be present in adults with repaired TOF and would be related to adverse markers of outcome. Method and Results— LGE was scored in the right and left ventricles (RV and LV) of 92 adult patients who had undergone TOF repair. RV LGE was seen in all patients at surgical sites located in the outflow tract (99%) or the site of ventricular septal defect patching (98%) and in the inferior RV insertion point (79%) and trabeculated myocardium (24%). LV LGE (53%) was located at the apex consistent with apical vent insertion (49%), in the inferior or lateral wall consistent with infarction (5%), or in other areas (8%). Patients with supramedian RV LGE score were older (38 versus 27 years, P<0.001) and more symptomatic (38% versus 8% in New York Heart Association class II or greater, P=0.001), had increased levels of atrial natriuretic peptide (7.3 versus 4.9 pmol/L, P=0.041), and had a trend to higher brain natriuretic peptide (12.3 versus 7.2 pmol/L, P=0.086), exercise intolerance (maximum &OV0312;o2 24 versus 28 mL · min−1 · kg−1, P=0.021), RV dysfunction (RV end-systolic volume 61 versus 55 mL/m2, P=0.018; RV ejection fraction 50% versus 56%, P=0.007), and clinical arrhythmia (26% versus 10%, P=0.039). Non–apical vent LV LGE also correlated with markers of adverse outcome. In a multivariate model, RV LGE remained a predictor of arrhythmia. Conclusions— RV and LV LGE were common after TOF repair and were related to adverse clinical markers, including ventricular dysfunction, exercise intolerance, and neurohormonal activation. Furthermore, RV LGE was significantly associated with clinical arrhythmia.

Role of Magnetic Resonance Angiography in the Diagnosis of Major Aortopulmonary Collateral Arteries and Partial Anomalous Pulmonary Venous Drainage

Background—Accurate diagnosis of major aortopulmonary collaterals (MAPCAs) and partial anomalous pulmonary venous drainage (PAPVD) in adult patients with congenital heart disease is important but problematic. Three-dimensional contrast-enhanced magnetic resonance angiography (MRA) provides a minimally invasive technique to allow detailed studies in a single breath-hold. Methods and Results—We assessed the role of contrast-enhanced 3D MRA in 29 consecutive adult patients with a diagnosis of MAPCAs (n=16) or PAPVD (n=13) made by echocardiogram, cardiac catheterization, or surgical inspection. MRA was performed with a 3D spoiled gradient-echo technique with intravenous gadolinium-DTPA (0.2 mmol/kg). In both types of pathology, there was excellent correlation between MRA and the cardiac catheterization, echocardiogram, or surgical inspection. Additional information was gained for patients with MAPCAs on confluence and size of pulmonary arteries (n=13 had central arteries), pulmonary artery stenosis (n=3), aneurysmal dilatation of pulmonary artery (n=1), and additional anomalous vascular abnormality (n=3). Shunt assessment, where present (9 of 16), showed patency in all cases (100%). For adults with PAPVD, further information was obtained on drainage origin (n=11). There were no complications. Conclusions—Contrast-enhanced 3D MRA provides a fast, noninvasive, radiation-free method of accurate and comprehensive diagnosis of MAPCAs and PAPVD in adult patients.

Are two drugs better than one? A review of combination therapies for hypertension

ABSTRACT Introduction: Current guidelines for pharmacotherapy briefly describe a role for combination antihypertensive therapy. However, guidance on whether combination therapy should be used at the time of initiating therapy or as add on, and the choice of combination therapy is scarce. Areas covered: Current literature suggests that intensive blood pressure control is the key to managing cardiovascular risk. Along with lifestyle management, pharmacotherapy is an central component in the treatment of hypertension. Here, we aim to review the pathophysiology of hypertension, rationale for using combination therapy, and the different combinations of antihypertensive drug classes that are available in the market. Papers from 1967 through 2016 listed on PubMed on this topic were reviewed. Expert opinion: Based on the review of the literature, combination antihypertensive therapies are more effective than monotherapy and are also well tolerated, safe and cost effective for treatment of hypertension. Further research is needed to help guide the choice of combination antihypertensive therapy in different patient populations based on age, gender, race and comorbidities.

Efficacy and safety of dronedarone in the treatment of patients with atrial fibrillation

ABSTRACT Introduction: Dronedarone, a derivative of amiodarone with structural modifications, was designed to have similar electrophysiological properties with a less toxic profile. Areas covered: Brief overview of the pharmacology of dronedarone followed by a summary of randomized clinical trials testing the efficacy of dronedarone in maintaining normal sinus rhythm and clinical outcomes associated with these trials. In depth discussion and commentary on trial findings which may seem contradictory at first approach and brief discussion of post-marketing surveillance studies. Expert opinion: Dronedarone is a moderately efficacious anti-arrhythmic agent which is safe for use in a carefully selected patient population, maintained in normal sinus rhythm, without advanced congestive heart failure, structural heart disease, permanent atrial fibrillation, digoxin use. It is especially useful in younger patients who lack other risk factors for cardiovascular events and, who stand to gain the most by avoiding long-term pulmonary and thyroid toxicities associated with more effective, but also significantly more toxic agents such as amiodarone.