Prashant Vaishnava

Anticoagulation during pregnancy in patients with a prosthetic heart valve

Effective anticoagulation is mandatory for pregnant women with mechanical heart valves. Oral anticoagulants offer the best maternal protection against thrombosis, but their use might be associated with an appreciable risk of fetal malformations and pregnancy loss. By contrast, heparin derivatives are associated with a reduced risk of fetal damage, but an increased risk of valve thrombosis in the mother, even with appropriate dose adjustment and monitoring of therapeutic efficacy. Given the varying risks of available anticoagulation strategies, and the paucity of data to inform the optimal approach, no single accepted treatment option exists for pregnant women with mechanical prosthetic valves. Although low-molecular-weight heparin is considered more efficacious than unfractionated heparin, treatment failures, even at therapeutic levels of factor Xa inhibition, have been reported. The risk of warfarin-related embryopathy might be overstated, particularly at doses ≤5 mg daily. We advocate an individualized anticoagulation strategy that takes into account the patients preferences, calls for the use of vitamin K antagonists throughout pregnancy (substituted with a heparin derivative only close to term) for those patients at the greatest risk of thromboembolism, and relies on close multidisciplinary collaboration between the cardiac and obstetric care teams.

Cardiac Risk of Noncardiac Surgery

Major perioperative cardiac events are estimated to complicate between 1.4% and 3.9% of surgeries. Because most surgeries are elective, there is the opportunity to implement strategies to reduce this risk. Accurate identification of patients at risk for such events will allow patients to be better informed about the benefit-to-risk ratio of procedures, and guide allotment of limited clinical resources, utilization of preventive interventions, and areas of future research. This review focuses on important features of the initial pre-operative clinical risk assessment, indications for diagnostic testing to quantify cardiac risk, and the methods and indications for pre-emptive therapies.

Surgery for asymptomatic degenerative aortic and mitral valve disease

Degenerative valvular heart disease, the most common form of valve disease in the Western world, can lead to aortic stenosis (AS) or mitral regurgitation (MR). In current guidelines for the management of patients with degenerative valvular disease, surgical intervention is recommended at the onset of symptoms or in the presence of left ventricular systolic impairment. Whether surgery is appropriate for asymptomatic patients remains a controversial issue. We argue the case for early pre-emptive intervention in selected, asymptomatic individuals with AS or MR, drawing on contemporary perioperative data, predictors of disease progression, and studies of the natural history of degenerative valvular heart disease.

Acute type B aortic dissection: insights from the International Registry of Acute Aortic Dissection

Acute type B aortic dissection comprises approximately one-third of all aortic dissection cases. Although this catastrophic cardiovascular condition was first described in the medical literature over two centuries ago, data on the optimal diagnostic and treatment modalities for type B dissection was slow to evolve throughout the latter half of the twentieth century, even as newer diagnostic techniques and management strategies became commonplace. To further elucidate contemporary practice patterns and outcomes of aortic dissection, the International Registry of Acute Aortic Dissection (IRAD) was established in 1996. Over the past two decades, IRAD publications have steadily increased our knowledge and understanding about aortic dissection. Specifically in recent years, analyses of IRAD data have gone beyond simply characterizing the patient with acute type B aortic dissection and have attempted to identify the means by which the outcome of such a patient could be improved. Thus, we present herein three areas in which IRAD data has recently advanced our understanding of acute type B aortic dissection: temporal classification especially for the subacute time period, risk stratification for identifying complicated cases, and thoracic endovascular aortic repair (TEVAR).

Compression of an anomalous left circumflex artery after aortic and mitral valve replacement.

A 52-year-old gentleman with a history of rheumatic fever presented with dyspnea. Transthoracic echocardiography revealed severe valvular aortic stenosis and severe mitral stenosis. A preoperative coronary angiogram revealed an anomalous left circumflex (LCX) artery arising from the right coronary sinus. The patient underwent aortic and mitral valve replacement. Postoperatively, a non-ST segment elevation myocardial infarction developed, and coronary angiography confirmed subtotal occlusion of the anomalous LCX. An emergent reoperation with surgical revascularization was performed. Intraoperatively, the mechanism of injury to the LCX was determined to be compression of the distal LCX by the sewing ring of the two prosthetic valves.

Quantitative assessment of right ventricular function in pectus excavatum

Pectus excavatum is a common congenital chest wall deformity. Underlying cardiac chambers, in particular the right atrium and right ventricle (RV), may be compressed between the vertebral column and the depressed sternum in patients with this thoracic deformity. Citing improvement in indices of cardiovascular function after corrective surgery, some investigators have suggested that the deformed chest may contribute to cardiopulmonary impairment. Although cardiopulmonary impairment certainly may contribute to symptoms in patients with pectus excavatum and guide the need for and timing of corrective surgery, guidelines for the assessment of resting cardiovascular function remain undefined. Furthermore, the qualitative echocardiographic assessment of RV function and volumes among patients with pectus excavatum may be technically difficult and limited by subjectivity. Quantitative echocardiographic parameters, such as tricuspid annular plane systolic excursion (TAPSE) and RV fractional area change, may offer a more accurate assessment of RV function in this anatomically distinct population. Cardiac magnetic resonance (CMR) imaging has emerged as the criterion standard in RV functional assessment and, more recently, has been validated in patients with pectus excavatum. We compared qualitative assessment of RV systolic impairment by visual echocardiographic inspection with quantitative assessment of RV function with CMR and echocardiographically derived TAPSE and RV fractional area change in a series of patients referred to our institution with mild to severe symptomatic pectus excavatum. Patients were being considered for corrective surgery. Our hypothesis was that the patients would be found to have normal RV function when assessed quantitatively, either through CMR or quantitative echocardiographic examination, despite impairment seen qualitatively.

Atrial Fibrillation Through the Years Contemporary Evaluation and Management

Information about a real patient is presented in stages (boldface type) to an expert clinician (Dr Valentin Fuster), who responds to the information, sharing his reasoning with the reader (regular type). A discussion by the authors follows. A 61-year-old man presents with 2 weeks of exertional dyspnea. Pertinent medical history includes hypertension, nephrolithiasis, and internal hemorrhoids. He takes no medications and has no known drug allergies. His father died after a myocardial infarction at 57 years of age. He formerly smoked 1 pack of cigarettes daily for 15 years but ceased tobacco use 10 years before presentation. He ingests 2 glasses of alcohol weekly and denies illicit drug use. His caffeine intake is limited. He is an architect and is married, with healthy children. On physical examination, his temperature is 98.0°F, blood pressure is 130/85 mm Hg bilaterally, pulse is irregular at 130 beats per minute, and respiratory rate is 18 breaths per minute with an oxygen saturation of 97% while breathing room air. He is a slender white man in no distress. His jugular venous pressure is elevated at 14 cm H 2 O. There is no thyromegaly, and the carotid upstrokes are brisk, without bruits. Cardiovascular examination reveals a rapid and irregular heart rhythm with variation in the intensity of the first heart sound. The point of maximal impulse is not displaced. The remainder of the chest and abdominal examination is within normal limits. The extremities are warm and show mild pitting edema. Laboratory testing is significant for normal renal function and electrolytes, but a hemogram reveals a mild thrombocytopenia of 90 000 platelets/μL. ECG demonstrates atrial fibrillation (AF) with an average ventricular rate of 123 bpm ( Figure 1 ). Figure 1. The 12-lead ECG showing atrial fibrillation with a rapid ventricular rate. Dr Valentin Fuster : This is a …

β-blockade to prevent perioperative death in non-cardiac surgery: questions, controversy, and not enough answers

The use of perioperative β-blockade in patients undergoing non-cardiac surgery are informed, in part, by the Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography (DECREASE) family of studies.1 Allegations of research fraud have discredited the DECREASE studies and diluted the evidence supporting the cardiovascular benefit of perioperative β blockade.2–4 All studies investigated in the DECREASE family were found to be insecure because of flaws ranging from fictitious methods to fabrication of data to no evidence of written informed consent.3 ,4 Current European and American guidelines continue to offer Class I recommendations for continuation of pre-existing β-blockade,5 ,6 and initiation of β-blockade in those patients known to have ischaemic heart disease or myocardial ischaemia according to preoperative testing,5 and those undergoing high-risk (primarily vascular) surgery.5 Recognising the limitations of the flawed DECREASE data, Bouri et al 3 performed a meta-analysis of secure intention-to-treat randomised controlled trial (RCT) data of β-blockade on perioperative mortality, non-fatal myocardial infarction, stroke and hypotension in patients undergoing non-cardiac surgery. Studies from the DECREASE family of studies were excluded; the meta-analysis included 10 529 patients from nine secure trials. Initiation of a course of β-blockade before surgery was associated with a significant 27% increase in mortality (relative risk (RR) 1.27, 95% CI 1.01 to 1.60, p=0.04). β-blockade reduced non-fatal myocardial infarction (RR …

Perioperative Cardiovascular Care for Patients Undergoing Noncardiac Surgical Intervention

The field of perioperative medicine has garnered legitimacy during the past 3 decades. Adverse cardiovascular events in the perioperative period account for significant morbidity and mortality. Although testing patients preoperatively to detect ischemia and identify those who may benefit from modifications in care is a tempting strategy, risk assessment should account for posterior probability. Validated risk stratification tools, such as the Revised Cardiac Risk Index or the National Surgical Quality Improvement Program risk calculator, can assist in the identification of patients for whom preoperative noninvasive testing is justified and may change the plan of care. Furthermore, current guidelines emphasize that prophylactic coronary revascularization should not be performed exclusively for the purposes of reducing the risk of perioperative events. There has been enthusiasm for medical therapies that may reduce the risk of adverse cardiovascular events in the perioperative period. Current guidelines encourage the perioperative use of β-blockade in patients already receiving such therapy and caution against initiating such therapy on the day of the surgical procedure. Reduction of morbidity and mortality in the perioperative period relies on an understanding of the myriad physiological perturbations in this period and thoughtful selection of patients for further testing and treatment.

Coronary Vasospasm Attributable to Fibromuscular Dysplasia The Long Bridge to Transplant

A 32-year-old woman with a 6-year medical history of perimenstrual chest pain and left ventricular systolic impairment after a presumed episode of idiopathic myocarditis presented to the emergency department with 2 hours of severe chest pain and an abnormal ECG with anterolateral ST-segment elevations (Figure 1A). During medical interview, the patient reported the use of cigarettes and cocaine in the past (not for the last 2 years) and very similar symptoms just 2 months earlier. At that time, troponin-I was elevated (12 ng/mL), and subsequent coronary angiogram revealed a dissection of the left circumflex artery, but percutaneous coronary intervention (PCI) could not be performed because of technical complexity, and the patient was commenced on aspirin and clopidogrel. Figure 1. A , Presenting ECG demonstrating anterolateral ST-segment elevations. B , Angiogram of left anterior descending artery displaying a thrombotic occlusion within the middle third of the vessel. C , Angiogram of left circumflex artery displaying a moth-eaten appearance with an angiographically normal artery proximal to the coronary artery, consistent with epicardial coronary fibromuscular dysplasia. D , Confirmation of vasospasm of the left circumflex artery with 25 µg of intracoronary ergonovine, relieved …