The prevention of contrast-induced nephropathy.

OBJECTIVE: Contrast-induced nephropathy (CIN) is a complication which may develop after exposure to iodinated contrast media. The resulting acute kidney injury (AKI) is associated with an increase in both short- and long-term morbidity and mortality, increased hospital length of stay, and greater health care costs. The pathophysiological mechanism associated with the development of CIN remains unknown. This narrative review summarizes the pathophysiology, risk factors, and current evidence for the prevention of CIN. DATA SOURCES: A MEDLINE literature search (2004-May 2014) was performed using search terms contrast-induced nephropathy and prevention. Additional references were identified from literature citations, review articles, and meta-analyses. STUDY SELECTION AND DATA EXTRACTION: Abstracts of English-language human clinical trials that examined therapies for the prevention of CIN were evaluated. Studies that did not investigate a preventative intervention for CIN were excluded. Emphasis was placed on recent publications. DATA SYNTHESIS: A multitude of therapies focused on the prevention of CIN have been investigated. Unfortunately, many of these studies have produced negative and/or inconsistent results. There is a paucity of adequately designed clinical studies evaluating strategies for the prevention of CIN. However, the best data supports use of preprocedural hydration with isotonic solution as the standard of care for prophylaxis. CONCLUSION: Given the poor prognosis associated with CIN, there is need for improved methods to prevent it. At present, the best tools to protect patients from unnecessary risk for CIN are careful assessment of renal function, judicious use of procedures that utilize contrast media, and adequate hydration with isotonic solution.

Vitamin D deficiency induces cardiac hypertrophy and inflammation in epicardial adipose tissue in hypercholesterolemic swine.

INTRODUCTION: Vitamin D is a sectosteroid that functions through Vitamin D receptor (VDR), a transcription factor, which controls the transcription of many targets genes. Vitamin D deficiency has been linked with cardiovascular diseases, including heart failure and coronary artery disease. Suppressor of cytokine signaling (SOCS)3 regulates different biological processes such as inflammation and cellular differentiation and is an endogenous negative regulator of cardiac hypertrophy. OBJECTIVE: The purpose of this study was to test the hypothesis that vitamin D deficiency causes cardiomyocyte hypertrophy and increased proinflammatory profile in epicardial adipose tissue (EAT), and this correlates with decreased expression of SOCS3 in cardiomyocytes and EAT. METHODS: Eight female Yucatan miniswine were fed vitamin D-sufficient (900 IU/d) or vitamin D-deficient hypercholesterolemic diet. Lipid profile, metabolic panel, and serum 25(OH)D levels were regularly measured. After 12 months animals were euthanized and histological, immunohistochemical and qPCR studies were performed on myocardium and epicardial fat. RESULTS: Histological studies showed cardiac hypertrophy, as judged by cardiac myocyte cross sectional area, in the vitamin D-deficient group. Immunohistochemical and qPCR analyses showed significantly decreased mRNA and protein expression of VDR and SOCS3 in cardiomyocytes of vitamin D-deficient animals. EAT from vitamin D-deficient group had significantly higher expression of TNF-α, IL-6, MCP-1, and decreased adiponectin in association with increased inflammatory cellular infiltrate. Interestingly, EAT from vitamin D-deficient group had significantly decreased expression of SOCS3. CONCLUSION: These data suggest that vitamin D deficiency induces hypertrophy in cardiomyocytes which is associated with decreased expression of VDR and SOCS3. Vitamin D deficiency is also associated with increased inflammatory markers in EAT. Activity of VDR in the body is controlled through regulation of vitamin D metabolites. Therefore, restoration of VDR function by supplementation of VDR ligands in vitamin D-deficient population might be helpful in reducing inflammation and cardiovascular risk.

Development and validation of a risk calculator for prediction of cardiac risk after surgery.

BACKGROUND: Perioperative myocardial infarction or cardiac arrest is associated with significant morbidity and mortality. The Revised Cardiac Risk Index is currently the most commonly used cardiac risk stratification tool; however, it has several limitations, one of which is its relatively low discriminative ability. The objective of the present study was to develop and validate a predictive cardiac risk calculator. METHODS AND RESULTS: Patients who underwent surgery were identified from the American College of Surgeons' 2007 National Surgical Quality Improvement Program database, a multicenter (>250 hospitals) prospective database. Of the 211 410 patients, 1371 (0.65%) developed perioperative myocardial infarction or cardiac arrest. On multivariate logistic regression analysis, 5 predictors of perioperative myocardial infarction or cardiac arrest were identified: type of surgery, dependent functional status, abnormal creatinine, American Society of Anesthesiologists' class, and increasing age. The risk model based on the 2007 data set was subsequently validated on the 2008 data set (n=257 385). The model performance was very similar between the 2007 and 2008 data sets, with C statistics (also known as area under the receiver operating characteristic curve) of 0.884 and 0.874, respectively. Application of the Revised Cardiac Risk Index to the 2008 National Surgical Quality Improvement Program data set yielded a relatively lower C statistic (0.747). The risk model was used to develop an interactive risk calculator. CONCLUSIONS: The cardiac risk calculator provides a risk estimate of perioperative myocardial infarction or cardiac arrest and is anticipated to simplify the informed consent process. Its predictive performance surpasses that of the Revised Cardiac Risk Index.

Ventricular metastasis without atrial or caval involvement: a rare presentation.

Right ventricular metastases from renal cell carcinoma without inferior vena cava (IVC) or right atrium involvement are rare. We discuss a 44-year-old male who presented with a left thigh mass, which was resected and the pathology revealed an epithelial sarcoma or a possible metastasis from another organ. His preradiotherapy cardiac evaluation showed mass in the right and left ventricles, which was confirmed by transesophagial echocardiogram. Computed tomography revealed a right renal mass in addition to the ventricular masses without any involvement of IVC or the atria. The patient underwent right radical nephrectomy without complications and systemic chemotherapy with interleukin-1 for metastatic renal cell carcinoma. He is doing well and follow-up echocardiogram showed significant reduction in the size of the cardiac metastases, even without surgical resection of these tumors. Thus, our article presents this unique case of asymptomatic ventricular metastases of renal cell carcinoma without any atrial or caval involvement and provides a new insight into the management of this syndrome.

Fibrosing mediastinitis presenting as pulmonary stenosis: stenting works.

A rare case of fibrosing mediastinitis from histoplasmosis with extrinsic compression of the right pulmonary artery is reported. A 41-year-old patient presented with worsening symptoms of cough, fever, migratory arthralgia, chest pain, and progressive dyspnea. The pulmonary artery involvement was suspected by transthoracic echo and was confirmed by transesophageal echo, CT scan of chest, and right heart catheterization. Diagnosis of histoplasmosis was confirmed by biopsy and serological tests. Patient has been free from symptoms of pulmonary stenosis for 4 years after successful pulmonary artery stenting.

Intensive smoking cessation intervention reduces mortality in high-risk smokers with cardiovascular disease.

PURPOSES: To compare an intensive smoking cessation intervention against usual care in hospitalized high-risk smokers with acute cardiovascular disease. METHODS: A total of 209 hospitalized smokers were randomized to the intensive intervention (n = 109) or to usual care (n = 100). Usual care consisted only of counseling and printed educational material provided prior to hospital discharge. Intensive treatment consisted of a minimum of 12 weeks of behavior modification counseling and individualized pharmacotherapy provided at no cost to the participant. Smoking status in all subjects was confirmed biochemically (ie, by measuring expired carbon monoxide) at 3, 6, 12, and 24 months after randomization. Outcomes included point prevalence and continuous abstinence smoking cessation rates, hospitalizations, and all-cause mortality. RESULTS: At each follow-up interval, point prevalence and continuous abstinence smoking cessation rates were significantly greater in the intensive-treatment group compared to the usual-care group. At 24 months, continuous abstinence smoking cessation rates were 33% in the intensive-treatment group and 9% in the usual-care group (p < 0.0001). Over the 2-year follow-up period, 41 patients in the usual-care group were hospitalized compared to 25 patients in the intensive-treatment group (relative risk reduction [RRR], 44%; 95% confidence interval [CI], 16 to 63%; p = 0.007). The all-cause mortality rate was 2.8% in the intensive-treatment group and 12.0% in the usual-care group (RRR, 77%; 95% CI, 27 to 93%; p = 0.014). The absolute risk reduction in mortality was 9.2% with a number needed to treat of 11. CONCLUSION: Hospitalized smokers, especially those with cardiovascular disease, should undergo treatment with a structured intensive cessation intervention. The duration of the initial treatment should be 3 months.

Pharmacological management of atrial fibrillation following cardiac surgery.

Atrial fibrillation (AF) is the most common complication following coronary artery bypass graft surgery (CABG). Post-CABG AF occurs most commonly on the second postoperative day and declines in incidence thereafter. A number of risk factors have been found to be associated with a higher frequency of post-CABG AF. These risk factors include advanced age, a prior history of AF, hypertension, and heart failure. Postoperative complications--including low cardiac output, use of an intra-aortic balloon pump, pneumonia, and prolonged mechanical ventilation--are also associated with higher rates of post-CABG AF. Post-CABG AF increases the risk of stroke, and the length and cost of hospitalization. Prophylactic administration of conventional beta-adrenoceptor antagonists (beta-blockers) or sotalol produces a consistent and significant reduction in the incidence of post-CABG AF; however, results with prophylactic amiodarone or magnesium are less consistent. Termination of post-CABG AF, once it occurs, can be accomplished with a number of antiarrhythmic agents. Ibutilide has been the most widely studied agent for this indication. Sotalol is not indicated for cardioversion of AF and has not been studied in the post-CABG setting. Electrical cardioversion and biatrial pacing have also been used to terminate post-CABG AF. Ventricular rate is best controlled with beta-blockers and calcium channel antagonists. Esmolol has a rapid onset of action and is easily titrated to effect. Digoxin can control the ventricular rate, but has a slow onset of action. There are limited data available to guide decisions regarding the optimal management of post-CABG AF.

Role of postoperative use of adrenergic drugs in occurrence of atrial fibrillation after cardiac surgery.

BACKGROUND: Use of adrenergic (inotropic and vasopressor) drugs is common after cardiac surgery. HYPOTHESIS: The study was undertaken to evaluate the role of postoperative adrenergic drug use as a predictor of postoperative atrial fibrillation (AF) after cardiac surgery. METHODS: The study population consisted of 199 patients post cardiac surgery. Postoperative adrenergic drug use and the baseline and clinical variables were analyzed as possible predictors of postoperative AF. RESULTS: Of 199 patients, postoperative AF occurred in 59 patients (incidence 30%). The adrenergic drugs were used in 127 (64%) patients. Postoperative AF occurred in 49 of the 127 patients (39%) with and in 10 of the 72 patients (14%) without adrenergic drug use (p < 0.01). By univariate analyses, postoperative adrenergic drug use, age, left ventricular hypertrophy, left atrial size, valve surgery, aortic valve replacement, cross clamp time, bypass time, postoperative ventricular pacing, and hours in intensive care unit were predictors of development of postoperative AF. Atrial pacing was a predictor of freedom from developing AF. By multivariate logistic regression analysis, adrenergic drug use was an independent predictor of postoperative AF (odds ratio [OR] 3.35, 95% confidence interval [CI] 1.38-8.12, p = 0.016). Two other independent predictors were valve surgery (OR 2.88, 95% CI 1.31-6.35, p = 0.002) and age (OR 10.73, 95% CI 10.37-11.10, p = 0.0001). Adrenergic drug use, valve surgery, ventricular pacing, and age were predictors of time duration from surgery to the occurrence of AF. Drugs with predominantly beta1-adrenergic receptor affinity were associated with a higher incidence of postoperative AF (dopamine 44%, dobutamine 41% vs. phenylepherine 20%, p = 0.001). CONCLUSION: Use of adrenergic drugs is an independent predictor of postoperative AF after cardiac surgery.

Role of postoperative vasopressor use in occurrence of atrial fibrillation after coronary artery bypass grafting.

Vasopressor use is common after coronary artery bypass grafting surgery. This study evaluated the role of postoperative vasopressor use as a predictor of occurrence of atrial fibrillation after coronary artery bypass grafting and demonstrates that vasopressor use is an independent predictor of such an occurrence.

Amiodarone versus sotalol for the treatment of atrial fibrillation after open heart surgery: the Reduction in Postoperative Cardiovascular Arrhythmic Events (REDUCE) trial.

OBJECTIVES: This prospective, randomized, double-blind, placebo-controlled study compared the efficacy and safety of amiodarone and sotalol in the prevention of atrial fibrillation (AF) following open heart surgery. BACKGROUND: The incidence of supraventricular arrhythmias following open heart surgery ranges from 20% to 40%, with AF being the most common. Both amiodarone and sotalol have been shown to be effective in reducing postoperative arrhythmias, but no direct comparison of these agents has been conducted. METHODS: A total of 160 patients were randomized, of whom 134 underwent coronary artery bypass graft surgery (CABG) alone, 17 underwent CABG and concomitant aortic valve replacement surgery (AVR), 9 underwent AVR only, and 1 patient's surgery was canceled. Patients with signs or symptoms of congestive heart failure (CHF), ejection fraction < or =30%, estimated creatinine clearance <30 mL/min, or serum creatinine > or =2.5 mg/dL were excluded. Patients were randomized to receive either sotalol 80 mg 2 times per day (n = 76) or intravenous amiodarone 15 mg/kg over 24 hours followed by oral amiodarone 200 mg 3 times per day (n = 83). Study drug was started at the time of surgery and continued for 7 days or until discharge, whichever came first. RESULTS: AF occurred in 17% of patients randomized to amiodarone and 25% of the patients randomized to sotalol (P =.21). However, the duration of AF was significantly shorter in amiodarone-treated patients (169 +/- 224 min) compared to sotalol treated patients (487 +/- 505 min; P =.04). In a subgroup analysis, the incidence of AF in patients undergoing AVR or CABG with AVR was significantly less with amiodarone (1/15, 7%) compared to sotalol (9/11, 82%) (P <.001). Blood pressure was lower immediately after surgery with amiodarone but comparable to sotalol at 24 hours. Of the hemodynamic indices measured, only stroke volume was significantly lower in patients randomized to sotalol at 24 hours (P =.035). CONCLUSIONS: Amiodarone and sotalol share similar efficacy and safety in reducing postoperative AF. Hemodynamic effects were similar between both drugs at 24 hours, with the exception that stroke volume was lower in sotalol-treated patients. In patients undergoing more complex surgery, postoperative AF occurred more frequently with sotalol than with amiodarone.

Comparison of conservative and aggressive smoking cessation treatment strategies following coronary artery bypass graft surgery.

PURPOSE: Patients who continue to smoke following coronary artery bypass graft surgery (CABG) have substantially poorer outcomes than patients able to stop smoking after CABG. This study evaluated the effectiveness of two smoking cessation treatment strategies in patients undergoing CABG. METHODS: Two smoking cessation treatment strategies were compared in smokers who underwent CABG. In the conservative treatment strategy, smokers undergoing CABG were followed up prospectively at monthly intervals. Patients who started smoking again at any time in the year following CABG were asked to enroll in an 8-week smoking cessation program. In the aggressive treatment strategy, smokers undergoing CABG were asked to enroll in an 8-week smoking cessation program starting immediately after hospital discharge. The structure and makeup of the smoking cessation program used in the conservative and aggressive treatment strategies were identical. The primary study outcome was smoking status assessed by self-report and confirmed by expired carbon monoxide at 1.5 months, 3 months, 6 months, and 12 months after surgery. RESULTS: Nineteen patients were enrolled in the conservative treatment strategy, with 2 patients unavailable for follow-up prior to the first follow-up visit. Of the remaining 17 patients, 14 patients (82%) resumed smoking at an average of 10.3 weeks after CABG. Eleven of these 14 patients (79%) agreed to participate in the smoking cessation program. Based on evaluable patients, 10 of the 17 patients (59%) in the conservative strategy group were not smoking at the 12-month follow-up. Twenty patients were enrolled in the aggressive treatment strategy. All patients agreed to participate in the smoking cessation program. All patients were available for follow-up. At the 12-month follow-up, 17 of 29 patients (85%) in this treatment strategy were not smoking. Point prevalence and continuous abstinence cessation rates were significantly greater in the aggressive treatment strategy compared to the conservative treatment strategy at all follow-up intervals after CABG. CONCLUSION: Based on our findings in a small number of patients, an aggressive smoking cessation intervention is associated with a superior smoking cessation rate compared to a conservative treatment strategy in smokers undergoing CABG. A larger study will be needed to confirm that an early aggressive smoking cessation intervention should be provided to all smokers undergoing CABG.

Electrocardiographic findings in patients >100 years of age without clinical evidence of cardiac disease.

Centenarians have a higher incidence of atrial fibrillation, left-axis deviation, premature beats, first-degree atrioventricular block, and nonspecific ST-T changes. Fewer men live long enough to reach 100 years of age, and they tend to have more significant conduction defects and old myocardial infarcts than women.

Amiodarone vs. sotalol as prophylaxis against atrial fibrillation/flutter after heart surgery: a meta-analysis.

BACKGROUND: The incidence of supraventricular arrhythmias remains high following open-heart surgery. The most common of these arrhythmias are atrial fibrillation and flutter (AFF), for which treatment is not well defined. Recent studies have focused on prophylactically treating patients in an attempt to reduce postoperative AFF. Several studies have shown that sotalol and amiodarone are both effective in reducing AFF following heart surgery. However, no studies have been done comparing both drugs. METHODS: A meta-analysis was done to compare the efficacy of sotalol and amiodarone after bypass graft surgery. Randomized controlled trials were included if patients were clearly monitored, and the incidence of AFF was noted. Ten studies were included in the final analysis. RESULTS: Both amiodarone and sotalol were more effective than placebo treatment in reducing the incidence of postoperative AFF. However, when the data were pooled, no differences were noted between amiodarone and sotalol for efficacy (sotalol, - 21.5%; 95% confidence interval [CI], - 28.3 to - 14.6; amiodarone, - 14.1%; CI, - 20.1 to - 8.1), length of stay (sotalol, - 0.13 d; CI, - 0.33 to 0.07 d; amiodarone, - 0.18; CI, - 0.38 to 0.02 d), or adverse drug reactions causing drug termination (sotalol, 9.7%; CI, 0.086 to 19.3; amiodarone, 1.95%; CI, - 0.48 to 4.38). CONCLUSIONS: This data would suggest that either drug could be used in a prophylactic regimen to reduce the incidence of AFF following heart surgery.