Propensity Score-Matched Comparison of Right Ventricular Strain in Women and Men Before and After Left Ventricular Assist Device Implantation.

Objective: Adverse events following left ventricular assist device (LVAD) implantation are more common in women than in men, but the impact of gender differences on right ventricular (RV) failure is not well defined. Therefore, we calculated RV strain before and after LVAD implantation in matched groups of men and women to determine if gender differences in RV failure after LVAD might account for the gender differences in overall outcomes. Methods: RV free wall longitudinal strain (FWS) and fractional area change were calculated preoperatively and 3 months postoperatively using speckle-tracking echocardiography analysis. A total of 172 patients (86 women, 86 men) were then propensity score matched (1:1) for comparison. Results: Although women had higher preoperative CHA2DS2-VASc scores and more frequent moderate mitral regurgitation than men (P = 0.018), the preoperative hemodynamic parameters were similar. Preoperative RV-FWS was -6.7% in women and -6.0% in men (P = 0.65). Postoperatively, women had more progression to severe tricuspid regurgitation (TR) than men (15% vs 7%, P = 0.06). At 3 months the RV-FWS was -7.7% in women and -7.0% in men (P = 0.59). Postoperative TR was moderate-severe in 20% of women and in 9% of men (P = 0.001). Women had a higher incidence of venous thromboembolism, cardiac arrhythmias, and bleeding compared with men. Women also had higher mortality rates at discharge and 30 days after surgery, but the survival rates at 5 years were similar. Conclusions: RV strain measurements track standard hemodynamic and echocardiographic parameters and confirm that gender differences in outcomes following LVAD implantation are not related to gender differences in RV failure rates.

Nitrous Oxide Impairs Axon Regeneration after Nervous System Injury in Male Rats.

BACKGROUND: Nitrous oxide can induce neurotoxicity. The authors hypothesized that exposure to nitrous oxide impairs axonal regeneration and functional recovery after central nervous system injury. METHODS: The consequences of single and serial in vivo nitrous oxide exposures on axon regeneration in four experimental male rat models of nervous system injury were measured: in vitro axon regeneration in cell culture after in vivo nitrous oxide administration, in vivo axon regeneration after sharp spinal cord injury, in vivo axon regeneration after sharp optic nerve injury, and in vivo functional recovery after blunt contusion spinal cord injury. RESULTS: In vitro axon regeneration 48 h after a single in vivo 70% N2O exposure is less than half that in the absence of nitrous oxide (mean ± SD, 478 ± 275 um; n = 48) versus 210 ± 152 um (n = 48; P < 0.0001). A single exposure to 80% N2O inhibits the beneficial effects of folic acid on in vivo axonal regeneration after sharp spinal cord injury (13.4 ± 7.1% regenerating neurons [n = 12] vs. 0.6 ± 0.7% regenerating neurons [n = 4], P = 0.004). Serial 80% N2O administration reverses the benefit of folic acid on in vivo retinal ganglion cell axon regeneration after sharp optic nerve injury (1277 ± 180 regenerating retinal ganglion cells [n = 7] vs. 895 ± 164 regenerating retinal ganglion cells [n = 7], P = 0.005). Serial 80% N2O exposures reverses the benefit of folic acid on in vivo functional recovery after blunt spinal cord contusion (estimate for fixed effects ± standard error of the estimate: folic acid 5.60 ± 0.54 [n = 9] vs. folic acid + 80% N2O 5.19 ± 0.62 [n = 7], P < 0.0001). CONCLUSIONS: These data indicate that nitrous oxide can impair the ability of central nervous system neurons to regenerate axons after sharp and blunt trauma.

Biatrial or Left Atrial Lesion Set for Ablation During Mitral Surgery: Risks and Benefits.

BACKGROUND: Controversy exists when performing surgical atrial fibrillation ablation whether there is an increase in postoperative complications using biatrial (BA) lesions compared with only left atrial (LA) lesions, and some studies indicate similar efficacy. This study compares the clinical outcomes of BA and LA ablation lesions in mitral valve surgery patients. METHODS: From 2004 through 2014, 2,137 patients had mitral valve surgery with or without other surgeries in a single center. Of those, 836 (39%) had preoperative atrial fibrillation, and of those, 724 (86%) underwent atrial fibrillation ablation surgery; 257 patients had BA lesion sets and 359 had LA lesion sets. Propensity score matching of BA and LA patients was performed. RESULTS: Baseline differences included more postoperative complications in the BA group, specifically, permanent pacemaker placement (13% versus 7%; p = 0.006). Freedom from atrial fibrillation off antiarrhythmic drugs (72% BA versus 75% LA; p = 0.50), postoperative ablation (7% BA versus 5% LA; p = 0.20), stroke (0.11 versus 0.11 per 10 person-years; p = 0.91), and survival were similar between the groups. After matching, patients in the LA group had a higher freedom from postoperative ablation (p = 0.015), but no difference in freedom from atrial fibrillation off antiarrhythmic drugs (79% BA versus 69% LA; p = 0.09), and no difference in permanent pacemaker placement (10% versus 12%; p = 0.57). CONCLUSIONS: Patients undergoing mitral surgery with LA or BA ablation had similar outcomes, survival, and complications. Limiting lesions to the LA is an effective alternative to BA ablation for patients undergoing ablation with concomitant mitral valve surgery.

Relationship of Provider and Practice Volume to Performance Measure Adherence for Coronary Artery Disease, Heart Failure, and Atrial Fibrillation: Results From the National Cardiovascular Data Registry.

BACKGROUND: There is a reported association between high clinical volume and improved outcomes. Whether this relationship is true for outpatients with coronary artery disease (CAD), heart failure (HF), and atrial fibrillation (AF) remains unknown. METHODS AND RESULTS: Using the PINNACLE Registry (2009-2012), average monthly provider and practice volumes were calculated for CAD, HF, and AF. Adherence with 4 American Heart Association CAD, 2 HF, and 1 AF performance measure were assessed at the most recent encounter for each patient. Hierarchical logistic regression models were used to assess the relationship between provider and practice volume and performance on eligible quality measures. Data incorporated patients from 1094 providers at 71 practices (practice level analyses n=654 535; provider level analyses n=529 938). Median monthly provider volumes were 79 (interquartile range [IQR], 51-117) for CAD, 27 (16-45) for HF, and 37 (24-54) for AF. Median monthly practice volumes were 923 (IQR, 476-1455) for CAD, 311 (145-657) for HF, and 459 (185-720) for AF. Overall, 55% of patients met all CAD measures, 72% met all HF measures, and 58% met the AF measure. There was no definite relationship between practice volume and concordance for CAD, AF, or HF (P=0.56, 0.52, and 0.79, respectively). In contrast, higher provider volume was associated with increased concordance for CAD and AF performance measures (P<0.001 for both), but not for HF (P=0.36). CONCLUSIONS: In the PINNACLE registry, performance was modest and variable. Higher provider volume was positively associated with quality, whereas practice volume was not.

The addition of hemiarch replacement to aortic root surgery does not affect safety.

OBJECTIVES: A hemiarch reconstruction, using deep hypothermic circulatory arrest, is the conventional approach for proximal aortic arch reconstruction, but it carries risks of neurologic events and coagulopathy. The addition of a hemiarch reconstruction to an aortic root replacement may prevent future aortic arch pathology. Outcomes of this approach at a tertiary care institution were examined to determine whether the addition of a hemiarch reconstruction to an aortic root replacement conferred any additional risk. METHODS: A total of 384 patients underwent an aortic root replacement between April 2004 and June 2012. Of them, 177 (46%) had hemiarch replacement. Propensity score matching yielded 133 pairs of patients receiving hemiarch and non-hemiarch. RESULTS: Sinus segment diameter was similar between groups; ascending aortic diameter was greater in the hemiarch group (median 50 vs 44 mm; P < .001). The hemiarch group had longer perfusion (median 186 vs 120.5 minutes; P < .001) and crossclamp times (median 140 vs 104 minutes; P < .001); median circulatory arrest was 13 minutes. There was no difference, hemiarch versus no hemiarch, in 30-day mortality (3.0% vs 1.5%; P = .41), stroke (2.3% vs 4.5%; P = .31), reoperation for bleeding (11% vs 10%; P = .84), or overall survival (5-year 88.0% [95% confidence interval, 81.9-94.0] vs 91.4% [95% confidence interval, 85.8-96.9], P = .24). CONCLUSIONS: In this series, aortic root replacement ± hemiarch reconstruction had low mortality. Addition of hemiarch replacement extended perfusion times but not at the expense of safety. Hemiarch reconstruction should be performed when the aortic root aneurysm extends into the distal ascending aorta.