Characteristics and Outcomes of Patients With Severe Bioprosthetic Aortic Valve Stenosis Undergoing Redo Surgical Aortic Valve Replacement.

BACKGROUND: With improved event-free survival of patients undergoing primary bioprosthetic aortic valve replacement (AVR), reoperation to relieve severe prosthetic aortic stenosis (PAS) is increasing. We sought to (1) identify of the characteristics of patients with severe bioprosthetic PAS undergoing redo AVR, and (2) assess the outcomes of these patients, along with factors associated with adverse outcomes. METHODS AND RESULTS: We studied 276 patients with severe bioprosthetic PAS (64±16 years, 58% men) who underwent redo-AVR between 2000 and 2012 (excluding mechanical PAS, severe other valve disease, and transcatheter AVR). Society of Thoracic Surgeons score was calculated. Severe PAS was defined as AV area <0.8 cm(2), mean AV gradient ≥40 mm Hg, or dimensionless index <0.25. A composite outcome of death and congestive heart failure admission was recorded. Mean Society of Thoracic Surgeons score and mean AV gradients were 8±8 and 53±17 mm Hg, whereas 28% had >II+ aortic regurgitation. Only 39% had an isolated redo AVR, the rest were combination surgeries (coronary bypass and/or aortic surgeries). At 4.2±3 years, 64 (23%) patients met the composite end point (48 deaths and 19 congestive heart failure admissions, 2.5% 30-day deaths). On multivariable Cox survival analysis, higher Society of Thoracic Surgeons score (hazard ratio, 1.35), higher grades of aortic regurgitation (hazard ratio, 1.29), and higher right ventricular systolic pressure (hazard ratio, 1.3) were associated with worse longer-term outcomes (all P<0.01). CONCLUSIONS: At an experienced center, in patients with severe bioprosthetic PAS undergoing redo AVR, the majority undergo combination surgeries but have excellent outcomes.

Predictors of long-term outcomes in patients with significant myxomatous mitral regurgitation undergoing exercise echocardiography.

BACKGROUND: Significant myxomatous mitral regurgitation leads to progressive left ventricular (LV) decline, resulting in congestive heart failure and death. Such patients benefit from mitral valve surgery. Exercise echocardiography aids in risk stratification and helps decide surgical timing. We sought to assess predictors of outcomes in such patients undergoing exercise echocardiography. METHODS AND RESULTS: This is an observational study of 884 consecutive patients (age, 58 ± 14 years; 67% men) with grade III+ or greater myxomatous mitral regurgitation who underwent exercise echocardiography between January 2000 and December 2011 (excluding functional mitral regurgitation, prior valvular surgery, hypertrophic cardiomyopathy, rheumatic valvular disease, or greater than mild mitral stenosis). Clinical and echocardiographic data (mitral regurgitation, LV ejection fraction, LV dimensions, right ventricular systolic pressure) and exercise variables (metabolic equivalents, heart rate recovery at 1 minute after exercise) were recorded. Composite events of death, myocardial infarction, stroke, and progression to congestive heart failure were recorded. Mean LV ejection fraction, indexed LV end-systolic dimension, resting right ventricular systolic pressure, peak stress right ventricular systolic pressure, metabolic equivalents achieved, and heart rate recovery were 58 ± 5%, 1.6 ± 0.4 mm/m(2), 31 ± 12 mm Hg, 46 ± 17 mm Hg, 9.6 ± 3, and 33 ± 14 beats, respectively. During 6.4 ± 4 years of follow-up, there were 87 events. On stepwise multivariable Cox analysis, percent of age/sex-predicted metabolic equivalents (hazard ratio, 0.99; 95% confidence interval, 0.98-0.99; P=0.005), heart rate recovery (hazard ratio, 0.29; 95% confidence interval, 0.17-0.50; P<0.001), resting right ventricular systolic pressure (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P=0.02), atrial fibrillation (hazard ratio, 1.91; 95% confidence interval, 1.07-3.41; P=0.03), and LV ejection fraction (hazard ratio, 0.96; 95% confidence interval, 0.92-0.99; P=0.04) predicted outcomes. CONCLUSIONS: In patients with grade III+ or greater myxomatous mitral regurgitation undergoing exercise echocardiography, lower percent of age/sex-predicted metabolic equivalents, lower heart rate recovery, atrial fibrillation, lower LV ejection fraction, and high resting right ventricular systolic pressure predicted worse outcomes.

Brain Shift and Pneumocephalus Assessment During Frame-Based Deep Brain Stimulation Implantation With Intraoperative Magnetic Resonance Imaging.

BACKGROUND: Brain shift and pneumocephalus are major concerns regarding deep brain stimulation (DBS). OBJECTIVE: To report the extent of brain shift in deep structures and pneumocephalus in intraoperative magnetic resonance imaging (MRI). METHODS: Twenty patients underwent bilateral DBS implantation in an MRI suite. Volume of pneumocephalus, duration of procedure, and 6 anatomic landmarks (anterior commissure, posterior commissure, right fornix [RF], left fornix [LF], right putaminal point, and left putaminal point) were measured. RESULTS: Pneumocephalus varied from 0 to 32 mL (median = 0.6 mL). Duration of the procedure was on average 195.5 min (118-268 min) and was not correlated with the amount of pneumocephalus. There was a significant posterior displacement of the anterior commissure (mean = -1.1 mm, P < .001), RF (mean = -0.6 mm, P < .001), LF (mean = -0.7 mm, P < .001), right putaminal point (mean = -0.9 mm, P = .001), and left putaminal point (mean = -1.0 mm, P = .001), but not of the posterior commissure (mean = 0.0 mm, P = .85). Both RF (mean = -.7 mm, P < .001) and LF (mean = -0.5 mm, P < .001) were posteriorly displaced after a right-sided burr hole. There was a correlation between anatomic landmarks displacement and pneumocephalus after 2 burr holes (rho = 0.61, P = .007), but not after 1 burr hole (rho = 0.16, P = .60). CONCLUSION: Better understanding of how pneumocephalus displaces subcortical structures can significantly enhance our intraoperative decision making and overall targeting strategy.

Impact of duration of mitral regurgitation on outcomes in asymptomatic patients with myxomatous mitral valve undergoing exercise stress echocardiography.

BACKGROUND: Significant mitral regurgitation (MR) typically occurs as holosystolic (HS) or mid-late systolic (MLS), with differences in volumetric impact on the left ventricle (LV). We sought to assess outcomes of degenerative MR patients undergoing exercise echocardiography, separated based on MR duration (MLS versus HS). METHODS AND RESULTS: We included 609 consecutive patients with ≥III+myxomatous MR undergoing exercise echocardiography: HS (n=487) and MLS (n=122). MLS MR was defined as delayed appearance of MR signal during mid-late systole on continuous-wave Doppler while HS MR occurred throughout systole. Composite events of death and congestive heart failure were recorded. Compared to MLS MR, HS MR patients were older (60±14 versus 53±14 years), more were males (72% versus 53%), and had greater prevalence of atrial fibrillation (16% versus 7%; all P<0.01). HS MR patients had higher right ventricular systolic pressure (RVSP) at rest (33±11 versus 27±9 mm Hg), more flail leaflets (36% versus 6%), and a lower number of metabolic equivalents (METs) achieved (9.5±3 versus 10.5±3), compared to the MLS MR group (all P<0.05). There were 54 events during 7.1±3 years of follow-up. On step-wise multivariable analysis, HS versus MLS MR (HR 4.99 [1.21 to 20.14]), higher LV ejection fraction (hazard ratio [HR], 0.94 [0.89 to 0.98]), atrial fibrillation (HR, 2.59 [1.33 to 5.11]), higher RVSP (HR, 1.05 [1.03 to 1.09]), and higher percentage of age- and gender-predicted METs (HR, 0.98 [0.97 to 0.99]) were independently associated with adverse outcomes (all P<0.05). CONCLUSION: In patients with ≥III+myxomatous MR undergoing exercise echocardiography, holosystolic MR is associated with adverse outcomes, independent of other predictors.

Importance of exercise capacity in predicting outcomes and determining optimal timing of surgery in significant primary mitral regurgitation.

BACKGROUND: In primary mitral regurgitation (MR), exercise echocardiography aids in symptom evaluation and timing of mitral valve (MV) surgery. In patients with grade ≥3 primary MR undergoing exercise echocardiography followed by MV surgery, we sought to assess predictors of outcomes and whether delaying MV surgery adversely affects outcomes. METHODS AND RESULTS: We studied 576 consecutive such patients (aged 57±13 years, 70% men, excluding prior valve surgery and functional MR). Clinical, echocardiographic (MR, LVEF, indexed LV dimensions, RV systolic pressure) and exercise data (metabolic equivalents) were recorded. Composite events of death, MI, stroke, and congestive heart failure were recorded. Mean LVEF was 58±5%, indexed LV end-systolic dimension was 1.7±0.5 mm/m(2), rest RV systolic pressure was 32±13 mm Hg, peak-stress RV systolic pressure was 47±17 mm Hg, and percentage of age- and gender-predicted metabolic equivalents was 113±27. Median time between exercise and MV surgery was 3 months (MV surgery delayed ≥1 year in 28%). At 6.6±4 years, there were 53 events (no deaths at 30 days). On stepwise multivariable survival analysis, increasing age (hazard ratio of 1.07 [95% confidence interval, 1.03 to 1.12], P<0.01), lower percentage of age- and gender-predicted metabolic equivalents (hazard ratio of 0.82 [95% confidence interval, 0.71 to 0.94], P=0.007), and lower LVEF (0.94 [0.89 to 0.99], P=0.04) independently predicted outcomes. In patients achieving >100% predicted metabolic equivalents (n=399), delaying surgery by ≥1 year (median of 28 months) did not adversely affect outcomes (P=0.8). CONCLUSION: In patients with primary MR that underwent exercise echocardiography followed by MV surgery, lower achieved metabolic equivalents were associated with worse long-term outcomes. In those with preserved exercise capacity, delaying MV surgery by ≥1 year did not adversely affect outcomes.