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Background: Hypertrophic cardiomyopathy (HCM) is commonly associated with mitral valve pathology. A large majority of patients with HCM have elongated anterior and posterior mitral leaflets. There remains debate regarding the necessity and role of concomitant mitral valve surgery at the time of septal myectomy. We aimed to describe the characteristics and share our surgical experiences with this specific group of patients. Methods: This retrospective single‐center study investigates adult patients with HCM, with or without elongated mitral valve leaflets (MVLs), who underwent elective septal myectomy with or without concomitant mitral valve intervention, between January 1, 2016, and June 30, 2020. Clinical data were obtained from institutional medical records as well as the Society of Thoracic Surgeons data registry. The clinical characteristics and in‐hospital surgical outcomes were compared between patients with an elongated MVL and those without. Results: In total, 379 patients underwent septal myectomy, and 22 patients with intrinsic mitral valve disease were excluded. In addition, 23 patients were excluded due to missing data. Of the remaining 334 patients, 131 (39.2%) had elongated MVL and concomitant MVL plication. Patients with elongated MVL had higher rates of preoperative mitral valve systolic anterior motion (SAM) (94.7% vs. 86.7%, p = 0.019) and higher preoperative provoked left ventricular outflow tract gradient (LVOTG) (134.5 mmHg versus 125.3 mmHg, p = 0.046). Post septal myectomy and mitral valve plication, they had lower rates of postoperative residual mitral regurgitation (3.8% vs. 12.8%, p = 0.006), comparable rates of residual SAM (28.2% vs. 31.5%, p = 0.524), postoperative provoked LVOTG (15.4 mmHg vs. 14.0 mmHg, p = 0.317), 30‐day major adverse cardiopulmonary events (2.3% vs. 3.9%, p = 0.409), and mortality (0% vs. 1.0%, p = 0.255). Conclusions: Elongated MVLs contribute more significantly to dynamic LVOT obstruction, as evidenced during provocative testing. Concomitant mitral valve intervention during septal myectomy can be performed safely and may provide an effective strategy to resolve SAM and stress‐induced LVOTG. [ABSTRACT FROM AUTHOR]

Purpose: The effect of preoperative cardiac troponin level on outcomes after coronary artery bypass grafting (CABG) is unclear. We investigated the impact of preoperative cardiac troponin I (cTnI) level as well as the time interval between maximum cTnI and surgery on CABG outcomes.Methods: All patients who underwent isolated CABG at our institution between 2009 and 2016 and had preoperative cTnI level available were identified using our Society of Thoracic Surgeons registry. Receiver operating characteristic (ROC) analysis was performed to identify a cTnI threshold level. Subjects were divided into groups based on this value and outcomes compared.Results: A total of 608 patients were included. ROC analysis identified 5.74 µg/dL as the threshold value associated with worse postoperative outcomes. Patients with peak cTnI >5.74 µg/dL underwent CABG approximately 1 day later, had twice the risk of adverse postoperative events, and had 2.8 day longer postoperative length of stay than those with peak cTnI ≤5.74 µg/dL. cTnI level was not associated with mortality or 30-day readmission. Time interval between peak cTnI and surgery did not affect outcomes.Conclusion: Elevated preoperative cTnI level beyond a certain threshold value is associated with adverse postoperative outcomes but is not a marker for increased mortality. Time from peak cTnI does not affect postoperative outcomes or mortality and may not need to be considered when deciding timing of CABG. [ABSTRACT FROM AUTHOR]

Background: Postoperative critical care management is an integral part of cardiac surgery that contributes directly to clinical outcomes. In the United States there remains considerable variability in the critical care infrastructure for cardiac surgical programs. There is little published data investigating the impact of a dedicated cardiac surgical intensive care service.Methods: A retrospective study examining postoperative outcomes in cardiac surgical patients before and after the implementation of a dedicated cardiac surgical intensive care service at a single academic institution. An institutional Society of Thoracic Surgeons database was queried for study variables. Primary endpoints were the postoperative length of stay, intensive care unit length of stay, and mechanical ventilation time. Secondary endpoints included mortality, readmission rates, and postoperative complications. The effect on outcomes based on procedure type was also analyzed.Results: A total of 1703 patients were included in this study-914 in the control group (before dedicated intensive care service) and 789 in the study group (after dedicated intensive care service). Baseline demographics were similar between groups. Length of stay, mechanical ventilation hours, and renal failure rate were significantly reduced in the study group. Coronary artery bypass grafting patients observed the greatest improvement in outcomes.Conclusions: Implementation of a dedicated cardiac surgical intensive care service leads to significant improvements in clinical outcomes. The greatest benefit is seen in patients undergoing coronary artery bypass, the most common cardiac surgical operation in the United States. Thus, developing a cardiac surgical intensive care service may be a worthwhile initiative for any cardiac surgical program. [ABSTRACT FROM AUTHOR]

Polymyxin B is used as a last treatment resort for multidrug‐resistant Gram‐negative bacterial infections. The objectives of this study were to examine the population pharmacokinetics of polymyxin B and investigate factor(s) influencing pharmacokinetic variability. Four serial blood samples each were collected from 35 adult patients at steady state. The concentrations of individual polymyxin B components were analyzed using a validated liquid chromatography / tandem mass spectrometry assay and combined to derive total concentrations. A maximum likelihood expectation maximization approach was used to fit the data. Various demographic variables were investigated as potential covariates for clearance and volume of distribution (Vd) using linear regression analysis. A one‐compartment model fit to the data satisfactorily (r2 = 0.96). The best‐fit mean ± SD for clearance and Vd were 2.5 ± 1.1 L/h and 34.3 ± 16.4 L, respectively. Creatinine clearance was found to be a statistically significant covariate of clearance, but the magnitude was deemed clinically insignificant. [ABSTRACT FROM AUTHOR]

Heart failure is one of the fastest-growing epidemics worldwide in health care today. Although a wide variety of animal models exist to create chronic heart failure, there are few truly successful, reproducible models with ischemic dilation and mitral regurgitation. Six healthy sheep (36 ± 5 kg) underwent multiple, strategic coronary artery ligations on the left ventricle (LV). Six to eight ligations were performed transmurally on three of four segments of the LV: anterior, lateral, and posterior. Side branches of the left anterior descending and circumflex arteries were ligated to create multiple, patchy areas of myocardial infarction. Cardiac global and regional systolic function was assessed by echocardiography and cardiac magnetic resonance imaging (MRI). The extent, the characteristics, and the location of the myocardial infarction were qualitatively and quantitatively assessed by late gadolinium enhancement imaging. The overall mortality rate was 16.7% (1/6 animals). Animals who survived showed a significantly reduced ejection fraction (mean 60 ± 5% to 28 ± 7%; P < 0.05); additionally, two out of the remaining five (40%) animals developed mild to moderate mitral regurgitation quantified by cardiac MRI. Furthermore, each animal developed clinical signs of heart failure (tachycardia, dyspnea, and tachypnea) consistent with global, dilated cardiomyopathy noted on MRI. Creating and reproducing a model of global, ischemic cardiomyopathy with functional mitral regurgitation is an arduous task. We have developed a promising model of ischemic heart failure using multiple ligations, which mimics the sequelae of human cardiomyopathy. Our proposed model is highly effective, reproducible, and may be used for experimental research on heart failure (cardiac assist devices, heart transplant, etc.). [ABSTRACT FROM AUTHOR]

Human immunodeficiency virus (HIV)-infected patients often take herbal medicines, which may interact with anti-retrovirals. American ginseng induces phase 2 and antioxidant enzymes in vitro and might increase the clearance of zidovudine and/or enhance antioxidant activity. Ten healthy volunteers received 300 mg of zidovudine orally before and after 2 weeks of treatment with a ginsen aside-enriched American ginseng extract 200 mg twice daily. This ginseng extract induced the phase 2 enzyme quinone reductase with an average concentration of doubling of enzyme activity of 190 µg/mL. Total ginsenoside content was 8.5 ± 0.5%. Pharmacokinetic profiles of zidovudine and oxidative stress marker concentrations were measured post-zidovudine dose. American ginseng does not significantly affect the formation clearance of zidovudine to its glucuronide (ratio post- to pre-American ginseng = 1.17; 90% confidence interval: 0.95-1.45; P = .21), total clearance (ratio = 0.97; 0.82-1.14; P = .70), or plasma zidovudine AUC0-8 (ratio = 1.03; 0.87-1.21; P = .77). Oxidative stress biomarkers are reduced post-American ginseng (F2-isoprostane ratio = 0.79; 0.72-0.86; P < .001; 8-hydroxy-deoxyguanosine ratio = 0.74; 0.59-0.92; P = .02). Two weeks of American ginseng does not alter zidovu dine pharmacokinetics but reduces oxidative stress markers. [ABSTRACT FROM AUTHOR]

Ventricular assist device (VAD) support in patients with a prosthetic heart valve had previously been considered a relative contraindication due to an increased risk of thromboembolic complications. We report our clinical experience of VAD implantation in patients with prosthetic heart valves, including both mechanical and bioprosthetic valves. The clinical records of 133 consecutive patients who underwent VAD implantation at a single institution from January 2002 through June 2009 were retrospectively reviewed. Six of these patients had a prosthetic valve in place at the time of device implantation. Patient demographics, operative characteristics, and postoperative complications were reviewed. Of the six patients, four were male. The mean age was 57.8 years (range 35-66 years). The various prosthetic cardiac valves included a mechanical aortic valve ( n = 2), a bioprosthetic aortic valve ( n = 3), and a mechanical mitral valve ( n = 1). The indications for VAD support included bridge to transplantation ( n = 2), bridge to recovery ( n = 1), and postcardiotomy ventricular failure ( n = 3). Three patients underwent left ventricular assist device placement and three received a right ventricular assist device. Postoperatively, standard anticoagulation management began with a heparin infusion (if possible) followed by oral anticoagulation. The 30-day mortality was 50% (3/6). The mean duration of support among survivors was 194.3 days (range 7-369 days) compared with 16.0 days (range 4-29 days) for nonsurvivors. Of the three survivors, two were successfully bridged to heart transplantation and one recovered native ventricular function. Among the three nonsurvivors, acute renal failure developed in each case, and two developed heparin-induced thrombocytopenia. This study suggests that VAD placement in patients with a prosthethic heart valve, either mechanical or bioprosthetic, appears to be a reasonable option. [ABSTRACT FROM AUTHOR]