Dale Kobrin

Minimally invasive approach provides at least equivalent results for surgical correction of mitral regurgitation: A propensity-matched comparison

OBJECTIVE Minimally invasive approaches to mitral valve surgery are increasingly used, but the surgical approach must not compromise the clinical outcome for improved cosmesis. We examined the outcomes of mitral repair performed through right minithoracotomy or median sternotomy. METHODS Between January 2002 and October 2011, 1011 isolated mitral valve repairs were performed in the University of Pennsylvania health system (455 sternotomies, 556 right minithoracotomies). To account for key differences in preoperative risk profiles, propensity scores identified 201 well-matched patient pairs with mitral regurgitation of any cause and 153 pairs with myxomatous disease. RESULTS In-hospital mortality was similar between propensity-matched groups (0% vs 0% for the degenerative cohort; 0% vs 0.5%, P = .5 for the overall cohort; in minimally invasive and sternotomy groups, respectively). Incidence of stroke, infection, myocardial infarction, exploration for postoperative hemorrhage, renal failure, and atrial fibrillation also were comparable. Transfusion was less frequent in the minimally invasive groups (11.8% vs 20.3%, P = .04 for the degenerative cohort; 14.0% vs 22.9%, P = .03 for the overall cohort), but time to extubation and discharge was similar. A 99% repair rate was achieved in patients with myxomatous disease, and a minimally invasive approach did not significantly increase the likelihood of a failed repair resulting in mitral valve replacement. Patients undergoing minimally invasive mitral repair were more likely to have no residual post-repair mitral regurgitation (97.4% vs 92.1%, P = .04 for the degenerative cohort; 95.5% vs 89.6%, P = .02 for the overall cohort). In the overall matched cohort, early readmission rates were higher in patients undergoing sternotomies (12.6% vs 4.4%, P = .01). Over 9 years of follow-up, there was no significant difference in long-term survival between groups (P = .8). CONCLUSIONS In appropriate patients with isolated mitral valve disease of any cause, a right minithoracotomy approach may be used without compromising clinical outcome.

Factors Associated With Vascular Complications in Patients Undergoing Balloon-Expandable Transfemoral Transcatheter Aortic Valve Replacement via Open Versus Percutaneous Approaches

Background—Vascular complications after transfemoral transcatheter aortic valve replacement are common and associated with significant morbidity and mortality. Little is known about the effect of access approach on vascular complications. Methods and Results—Between 2007 and 2013, 331 patients underwent transfemoral transcatheter aortic valve replacement via open surgical (OS) or fully percutaneous (PC) approaches. Patient data and clinical outcomes were collected. Valve Academic Research Consortium–defined vascular complications were noted. Multivariable analysis with propensity matching was performed, and vascular complications, mortality, and length of stay were assessed. One hundred twenty patients were treated with the OS approach and 211 patients via the PC approach. There were fewer major vascular complications (11% versus 20%; P=0.03) and shorter length of stay (7.5 versus 9.9 days; P=0.003) in the PC group when compared with those in the OS group. In multivariable analysis, vascular complications were more likely in women (odds ratio, 2.2; P=0.02) and with increasing differences between sheath outer diameter and minimal artery diameter (overall vascular complications: odds ratio, 1.4; P=0.02 and major vascular complications: odds ratio, 2.0; P<0.001). Propensity-matched analysis demonstrated no difference in vascular complications between the OS and the PC groups (22% versus 19%; P=0.73) but significantly reduced length of stay in the PC group (7.9 versus 10.0 days; P=0.04). Conclusions—Transfemoral transcatheter aortic valve replacement performed via the PC route is associated with similar risk of vascular complications and significantly lower postprocedural length of stay than the OS route. The degree of sheath oversizing with respect to iliofemoral minimal artery diameter and female sex are associated with vascular complications regardless of access approach.

Ventricular assist device implant in the elderly is associated with increased, but respectable risk: a multi-institutional study.

BACKGROUND There are an increasing number of elderly patients with end-stage heart failure. Destination mechanical circulatory support is often the only therapy available for these patients who are not transplant candidates. The outcomes after continuous flow left ventricular assist device (CF LVAD) implant in older patients remains unclear. We undertook this multi-institutional study to quantify short-term and midterm outcomes after CF LVAD implant in the elderly. METHODS We retrospectively analyzed all patients in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) national registry that underwent implant of a CF LVAD (June 2006 to April 2012). Patients were divided into 2 cohorts based upon age (<70 years [n = 4,439] and ≥ 70 years (n = 590]). Preoperative, intraoperative, and postoperative variables were analyzed. The primary endpoint, survival, was compared between cohorts. RESULTS Patients age 70 and older were more hemodynamically stable pre-VAD implant as evidenced by INTERMACS profile and inotrope dependence. Perioperative outcomes, including median bypass time (89 vs 89 minutes) and length of stay (0.657 vs 0.657 months) were similar between cohorts (p = not significant). Kaplan-Meier analysis revealed a significant difference in 2-year survival between patients aged 70 years or greater (63%) and less than 70 (71%, p < 0.001). Multivariable Cox proportional hazard analysis revealed age as an independent predictor of mortality during follow-up (p < 0.001). Nonetheless, midterm cumulative survival in the older cohort was still reasonable (63% at 2 years). CONCLUSIONS Multi-institutional analysis revealed advanced age as a predictor of increased mortality after CF LVAD implantation. Careful patient selection is critical in the elderly to optimize long-term outcomes after CF LVAD implantation.

Transcatheter and Surgical Aortic Valve Replacement in Dialysis Patients: A Propensity-Matched Comparison.

BACKGROUND Transcatheter aortic valve replacement (TAVR) clinical trials in North America excluded patients on dialysis and, consequently, the outcomes of TAVR in dialysis-dependent patients remain unknown. METHODS All Medicare fee-for-service patients undergoing TAVR (n = 5,005) or surgical aortic valve replacement (SAVR) (n = 32,634) between January 1, 2011, and November 30, 2012, were identified using procedural codes collected by the Centers for Medicare & Medicaid Services. Dialysis status and comorbidities were identified using diagnosis codes present on arrival for TAVR hospitalization. Patients supported on dialysis who underwent TAVR (n = 224) were compared with non-dialysis patients who underwent TAVR as well as a propensity-matched group of contemporaneous dialysis patients who underwent SAVR (n = 194 pairs). RESULTS The TAVR patients on dialysis were younger than non-dialysis TAVR patients (79.2 years vs 84.1 years; p < 0.01) but had higher prevalence of comorbidities. Dialysis TAVR patients had increased mortality at 30 days (13% vs 6%, p < 0.01) and significantly worse survival by Kaplan-Meier analysis. Multivariable regression found dialysis to be independently associated with worse survival (hazard ratio, 1.73; 95% confidence interval, 1.33% to 2.25%, p < 0.01) in TAVR patients. Propensity-matched dialysis SAVR and dialysis TAVR patients had no significant differences in demographic or risk factors. Matched dialysis TAVR patients had shorter length of stay (6 interquartile range, 4 to 10] vs 10 [IQR 7 to 18] days; p < 0.01) and comparable survival. CONCLUSIONS TAVR in dialysis patients is associated with decreased survival compared with non-dialysis patients; however, it is comparable with SAVR in high risk dialysis patients based on a propensity-matched comparison.

Quantitative evaluation of change in coexistent mitral regurgitation after aortic valve replacement

OBJECTIVES Management of intermediate degrees of mitral regurgitation during aortic valve replacement for aortic stenosis remains controversial. We sought to evaluate the degree of reduction of mitral regurgitation in patients undergoing aortic valve replacement, as well as a mathematical relationship between aortic valve gradient reduction and the degree of mitral regurgitation decrement. METHODS We retrospectively analyzed demographic, intraoperative, and echocardiographic data on 802 patients who underwent aortic valve replacement or aortic root replacement between January 2010 and March 2011. A total of 578 patients underwent aortic valve replacement or aortic root replacement without intervention on the mitral valve. We excluded 88 patients with severe aortic insufficiency, 3 patients who underwent ventricular assist device placement, 4 patients who underwent prior mitral valve replacement, and 21 patients with incomplete data, yielding 462 patients for analysis. For each patient, the degree of pre- and postoperative mitral regurgitation was graded on a standard 0 to 4+ scale. RESULTS Of the 462 patients, 289 patients had at least mild mitral regurgitation. On average, mitral regurgitation decreased 0.24 degrees per patient for this cohort of 289 patients. Of the 56 patients with at least moderate mitral regurgitation, mitral regurgitation decreased 0.54 degrees per patient. Of 62 patients who underwent isolated aortic valve replacements, who had at least mild mitral regurgitation, and who had no evidence of structural mitral valve disease, mitral regurgitation decreased 0.24 degrees per patient. Linear regression analysis revealed no relationship between reduction in mitral regurgitation and gradient reduction across the aortic valve. CONCLUSIONS Reduction in mitral regurgitation after relief of aortic outflow tract obstruction is modest at best. Further, the magnitude of gradient change across the aortic valve has little influence on the degree of reduction in mitral regurgitation. These observations argue at minimum for performing a prospective evaluation of the clinical benefits of addressing moderate mitral regurgitation at the time of aortic valve intervention and may support a more aggressive approach to concomitant mitral surgery.

Increasing Frequency of Left Ventricular Assist Device Exchanges in the United States

BACKGROUND Recent reports indicate an increased prevalence and earlier onset of pump thrombosis and associated pump exchanges after left ventricular assist device (LVAD) implantation. Questions remain regarding the current rate and clinical effect of pump exchanges. METHODS All United States Medicare fee-for-service patients undergoing LVAD implantations (n = 3,166) between January 2009 and December 2012 were identified by procedural codes present on carrier claims collected by the Centers for Medicare & Medicaid Services. Pump exchange, pump removal, heart transplantation, and death were collected from subsequent carrier claim and denominator files. Comorbidities present before implantation were generated using the Elixhauser comorbidity index. RESULTS Compared with patients who received LVADs before March 1, 2011, LVAD recipients after March 1, 2011, were older on average (63.9 vs 62.2 years, p < 0.01), more likely to be male (82.3% vs. 79.4%, p = 0.04), and had a higher incidence of common comorbidities. The later cohort had higher occurrence of pump exchange by Kaplan-Meier time-to-event estimates and Fisher exact tests at 3 months (1.8 vs 0.8, p = 0.02), 6 months (3.3 vs 1.0, p < 0.01), and 12 months (4.9 vs 2.2, p < 0.01). Cox regression analysis found time-dependent pump exchange was associated with worse survival (hazard ratio, 2.5; 95% confidence interval, 1.8 to 3.62; p < 0.01) after adjusting for age, gender, and comorbidities. CONCLUSIONS Although LVAD exchanges remain relatively uncommon, a significant increase in the incidence of the procedure has occurred since March 1, 2011. Pump exchanges are highly associated with death, and further research is required to understand the cause of this disturbing trend and surveillance to determine its trajectory.

Effect of Clinical Trial Experience on Transcatheter Aortic Valve Replacement Outcomes

Background—Transcatheter aortic valve replacement (TAVR) was approved by the Food and Drug Administration (FDA) in November 2011 after a collaborative technology development process involving professional medical societies, the medical device industry, and the FDA. After FDA approval, TAVR was adopted by numerous hospitals that had not participated in TAVR clinical trials. It is uncertain if outcomes at these hospitals were comparable with those at clinical trial hospitals. Methods and Results—All patients with Medicare physician claims for TAVR between January 1, 2011, and November 30, 2012, were identified, and postoperative mortality was assessed using Medicare enrollment data. Risk-adjusted mortality was calculated via a multivariable model that adjusted for demographics and comorbidities. We identified 5009 patients who underwent TAVR, with 3617 TAVRs performed at 68 hospitals that had participated in clinical trials and 1392 TAVRs performed at 140 nontrial hospitals. The preoperative characteristics of patients at trial versus nontrial hospitals were similar. There were no significant differences in risk-adjusted 30-day mortality (5.9% versus 5.6%, odds ratio, 0.88; 95% confidence interval, 0.66–1.15; P=0.34) or 180-day mortality (16.5% versus 15.8%, odds ratio, 0.99; 95% confidence interval, 0.75–1.3; P=0.94). Conclusions—Patients undergoing TAVR at nontrial hospitals had comparable clinical outcomes to patients undergoing TAVR at clinical trial hospitals. This finding contrasts with several other cardiovascular devices and procedures for which higher mortality was observed at hospitals that did not participate in clinical trials. The unique policy and regulatory environment governing TAVR adoption by hospitals may have contributed to better outcomes during the technology diffusion process.