Comparison of regadenoson and nitroprusside to adenosine for measurement of fractional flow reserve: A systematic review and meta-analysis.

BACKGROUND: FFR is useful in defining the physiological significance of intermediate coronary stenosis and requires induction of maximal hyperemia and measurement of pressure proximal and distal to the stenosis. Hyperemia normally is induced by either IV or IC adenosine, a medication associated with short-term side effects. IV regadenoson and IC nitroprusside have been suggested as viable alternatives. This meta-analysis aims to identify all studies comparing use of intravenous (IV) regadenoson or intracoronary (IC) nitroprusside with IV adenosine to determine differences related to the agent utilized for assessment of fractional flow reserve (FFR). METHODS: We searched PubMed, EMBASE, Web of Science, SCOPUS, ClinicalTrials.gov and the Cochrane Library databases for studies comparing IV regadenoson or IC nitroprusside to IV adenosine for FFR assessment. The main outcome was difference in mean FFR measurement. The main secondary outcomes were composite side-effect profile and reclassification of lesions. RESULTS: Seven studies were included in the analysis, with a total of 375 patients. Compared to IV adenosine, there was no difference in the mean FFR derived from IV regadenoson (p=1.0) or IC nitroprusside (p=0.48). IV regadenoson was associated with 53% lower risk of pooled side effects compared to IV adenosine (p=0.05). IC nitroprusside was associated with 97% lower risk of pooled side effects compared to IV adenosine (p<0.001). CONCLUSIONS: IV regadenoson and IC nitroprusside produce similar pressure-derived FFR measurements compared to IV adenosine and have a favorable side effect profile. Both can be considered as alternative agents to IV adenosine for FFR measurement. Further clinical validation is warranted.

Colchicine for Prevention of Post-Operative Atrial Fibrillation: A Meta-Analysis.

OBJECTIVES: This study sought to investigate the efficacy and safety of colchicine for prevention of post-operative atrial fibrillation. BACKGROUND: Proinflammatory processes induced during cardiac surgery may contribute toward post-operative atrial fibrillation (AF). Colchicine is a potent anti-inflammatory agent, which may have a role in post-operative AF prevention. METHODS: We searched PubMed, EMBASE, Web of Science, CINAHL, ClinicalTrials.gov, and the Cochrane Library databases for randomized controlled trials (RCT) comparing colchicine versus placebo for prevention of post-operative AF. The main outcome measure of interest was the development of AF within 12 months after cardiac surgery. The overall risk ratio (RR) for the development of post-operative AF was computed using a random-effects model. RESULTS: Data analyzed from 3 randomized studies with a total of 912 patients, where 457 patients received colchicine and 455 patients received placebo, showed that perioperative colchicine therapy was associated with a reduced incidence of post-operative AF (RR: 0.65; 95% confidence interval [CI]: 0.46 to 0.91; p < 0.01). Although colchicine therapy was associated with increased incidence of gastrointestinal intolerance (RR: 2.20; 95% CI: 1.31 to 3.70; p = 0.003), it was not associated with early treatment discontinuation (RR: 1.37; 95% CI: 0.95 to 1.96; p = 0.09). CONCLUSIONS: In conclusion, current evidence suggests that colchicine therapy is efficacious for the prevention of post-operative AF, and may be considered as adjunctive prophylaxis. Further studies may be required to determine the optimal treatment protocol to reduce the incidence of gastrointestinal intolerance.

Benefit of statin pretreatment in prevention of contrast-induced nephropathy in different adult patient population: systematic review and meta-analysis.

OBJECTIVE: Previous studies have suggested that statin pretreatment prevents contrast-induced nephropathy (CIN). However, single randomised trials are limited in their number of patients. This meta-analysis aims to assess the role of statin use in CIN prevention, as well as to determine patient subgroups that will benefit from statin pre-treatment. METHODOLOGY: We searched PubMed, EMBASE, Web of science and the Cochrane Central Register of Controlled Trials databases for randomised controlled trials (RCT) comparing statin pretreatment versus placebo for preventing CIN. Our main outcome was the risk of CIN within 1-5 days after contrast administration. RESULTS: Data analysed from nine randomised studies with a total of 5143 patients, where 2559 received statins and 2584 received placebo, showed that statin pretreatment was associated with significant reduction in risk of CIN (MH-RR=0.47, 95% CI 0.34 to 0.64, Z=4.49, p<0.00001). This beneficial effect of statin was also seen in patients with baseline renal impairment (MH-RR=0.46, 95% CI 0.29 to 0.72, p=0.0008) and also those who were cotreated with NAC (MH-RR=0.46, 95% CI 0.25 to 0.83, p=0.01). CONCLUSIONS: Statin pretreatment leads to significant reduction in CIN, and should be strongly considered in all patients who are planned for diagnostic and interventional procedures involving contrast-media administration.

Meta-analysis of revascularization versus medical therapy for atherosclerotic renal artery stenosis.

The aim of the study was to compare the efficacy of revascularization versus medical therapy in patients with atherosclerotic renal artery stenosis (ARAS). ARAS is the most common cause of secondary hypertension and is associated with several complications, such as renal failure, coronary artery disease, cardiac destabilization, and stroke. Medical therapy is the cornerstone for management of ARAS; however, numerous trials have compared medical therapy with revascularization in the form of percutaneous renal artery angioplasty (PTRA) or percutaneous renal artery angioplasty with stent placement (PTRAS). Medline (PubMed and Ovid SP), Embase, Cochrane Central Register of Controlled Clinical Trials (CENTRAL), and Cochrane Database of Systematic Review (CDSR) were searched till present (November 2013) to identify clinical trials where medical therapy was compared with revascularization (PTRA or PTRAS). We performed a meta-analysis using a random effects model. The heterogeneity was assessed using I2 values. The initial database search identified 540 studies and 7 randomized controlled trials, and 2,139 patients were included in the final analysis. Angioplasty with or without stenting was not superior to medical therapy with respect to any outcome. The incidence of nonfatal myocardial infarction was 6.74% in both the stenting and medical therapy group (odds ratio=0.998, 95% confidence interval 0.698 to 1.427, p=0.992), and incidence of renal events in stenting population was found to be 19.58% versus 20.53% in medical therapy (odds ratio=0.945, 95% confidence interval 0.755 to 1.182, p=0.620). In conclusion, PTRA or PTRAS does not improve outcomes compared with medical therapy in patients with ARAS. Future studies should investigate to identify patient subgroups that may benefit from such an intervention.

Coronary steal resulting from LIMA-to-SVG-to-LAD-to-ventricular fistula physiology associated with malpositioned prosthetic aortic valve.

Following aortic valve replacement (AVR) and a single vessel bypass (SVG) to the left-anterior descending artery (LAD), the patient had a non-ST segment myocardial infarction with graft occlusion and underwent left internal mammary artery (LIMA) to SVG to LAD. When we evaluated her at our institution for ischemic symptoms, we were able to determine the probable sequence of events and the reason for her symptoms. Her AVR was interfering with normal flow into the left main with associated coronary steal from the distal LAD. The AVR had to be revised and the patient's symptoms improved.

Anomalous insertion of the papillary muscle causing left ventricular outflow obstruction: visualization by real-time three-dimensional echocardiography.

Anomalous insertion of the papillary muscle (PM)/chordae tendineae is a rare but important cause of dynamic left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy or cardiac amyloidosis. These anomalies are often challenging to diagnose with 2-D Echo, yet accurate diagnosis is critical in determining whether to proceed with an extended septal myectomy instead of a standard septal myectomy for relief. We report two cases of anomalous insertion of the PM causing LVOT obstruction with diagnosis facilitated by real-time 3-D echocardiograms.

Preoperative dobutamine stress echocardiographic findings and subsequent short-term adverse cardiac events after orthotopic liver transplantation.

Cardiovascular (CV) complications are the leading cause of non-graft-related death in orthotopic liver transplant (OLT) patients. Pretransplant cardiac evaluation using dobutamine stress echocardiography (DSE) is commonly utilized for risk stratification of OLT candidates. To determine if clinical and echocardiographic variables identify patients with increased CV risk, we performed a retrospective chart review of all 284 patients that underwent OLT at our institution between June 1999 and August 2005. Of these patients, 157 had a DSE prior to their OLT. Serious adverse CV events occurring during surgery and up to 4 months post-transplantation were defined as cardiac-related death, myocardial infarction (MI), new heart failure, or asystole or unstable ventricular arrhythmia requiring acute treatment. Sixteen of 157 patients (10%) had an adverse CV event with 2 deaths. These included ventricular tachycardia (n = 8), asystole (n = 2), MI (n = 5), and new heart failure (n = 1). Nine of the 16 CV events occurred at the time of surgery (including both deaths), 5 occurred postoperatively, and 3 occurred after hospital discharge. Variables that correlated with increased CV events were inability during DSE to achieve >82% of the maximum predicted heart rate (22% versus 6%, P = 0.01), a peak rate pressure product during DSE of <16,333 (17% versus 5%, P = 0.02), and a Model for End-Stage Liver Disease (MELD) score of >24 at the time of OLT. A multivariate model calculated from the DSE maximum achieved heart rate (MAHR) and MELD score (result = 3.78 + 0.07 MELD - 0.05 MAHR) identified a 47% risk for a value > 0 versus a 6% risk for a value < 0 (P < 0.001). In conclusion, the maximum heart rate achieved during DSE together with the MELD score may be a predictor of adverse CV events up to 4 months post-OLT. A large prospective study is needed to more decisively support this conclusion.

Paraneoplastic coma and acquired central alveolar hypoventilation as a manifestation of brainstem encephalitis in a patient with ANNA-1 antibody and small-cell lung cancer.

INTRODUCTION: Paraneoplastic neurological disorders are a well recognized complication of malignancy. METHODS: A case report to expand the currently described clinical manifestations of type 1 antineuronal antibody (ANNA-1)-associated paraneoplastic encephalomyelitis to include coma. RESULTS: We present an unusual case of fluctuating coma and rapid fulminant progression to acute respiratory failure from central alveolar hypoventilation caused by ANNA-1 paraneoplastic encephalomyelitis associated with small-cell lung carcinoma. Paraneoplastic infiltration of the brainstem and cerebellum, including respiratory and arousal centers, was documented on autopsy. CONCLUSIONS: Paraneoplastic encephalomyelitis should be considered as a possible cause of coma and central alveolar hypoventilation.