Prolonged Ischemia Times for Heart Transplantation: Impact of the 2018 Allocation Change.

BACKGROUND: In 2018, the United Network for Organ Sharing implemented a change in heart allocation policy resulting in increased organ ischemia times in early analyses. This study evaluated the effect of ischemia time on 1-year mortality in the context of allocation policy changes implemented in 2006 and 2018. METHODS: The United Network for Organ Sharing registry was used to identify adults undergoing heart transplantation from 2000 to 2020. Patients were stratified by the allocation policy era in which they received a transplant (2000-June 2006, July 2006-October 2018, October 2018-2020) and by ischemia time, defined as normal (≤4 hours) and prolonged (>4 hours). One-year survival was estimated using Kaplan-Meier analysis. Cox regression was used to determine risk-adjusted hazards for ischemia time on 1-year mortality. RESULTS: There were 40 052 patients included for analysis. Ischemia times were normal in 32 585 (81.36%) and prolonged in 7467 (18.64%) patients. The proportion of transplantations with prolonged ischemia times increased with each subsequent policy era. After the 2018 policy change, 1-year survival was 90.92% with normal ischemia times vs 87.52% with prolonged ischemia times (P < .001). Ischemia time independently predicted 1-year mortality in each era with a hazard ratio of 1.20 per hour (P = .004) in the current era. CONCLUSIONS: Prolonged ischemia times occur in a minority of cases but are increasing in frequency. The independent risk of prolonged ischemia time on 1-year mortality persists despite advances in storage technology and should remain a consideration in donor-recipient matching.

National trends and outcomes of heart-kidney transplantation using hepatitis C positive donors.

BACKGROUND: This study evaluated the outcomes of combined heart-kidney transplantation in the United States using hepatitis C positive (HCV+) donors. METHODS: Adults undergoing combined heart-kidney transplantation from 2015 to 2020 were identified in the United Network for Organ Sharing registry. Patients were stratified by donor HCV status. Kaplan-Meier curves with multivariable Cox regression models were used for risk-adjustment in a propensity-matched cohort. RESULTS: A total of 950 patients underwent heart-kidney transplantation of which 7.8% (n = 75) used HCV+ donors; 68% (n = 51) were viremic and 32% (n = 24) were non-viremic donors. Unadjusted 1-year recipient survival was similar between HCV+ versus HCV- donors (84% vs 88%, respectively; P = .33). Risk-adjusted analysis in the propensity-matched cohort showed HCV+ donor use did not confer increased risk of 1-year mortality (hazard ratio .63, 95% CI .17-2.32; P = .49). Sub-group analysis showed viremic and non-viremic HCV+ donors had similar 1-year survival as well (84% vs 84%; P = .95). CONCLUSIONS: Compared with recipients of HCV- donor dual heart-kidney transplants, recipients of HCV+ organs had comparable 1-year survival and clinical outcomes after combined transplantation. Although future studies should evaluate other outcomes related to HCV+ donor use, this practice appears safe and should be expanded further in the heart-kidney transplant population.

Heart Transplantation for Peripartum Cardiomyopathy: Outcomes Over 3 Decades.

BACKGROUND: This study evaluated trends and outcomes of patients undergoing heart transplantation for peripartum cardiomyopathy (PPCM) over the past 3 decades. METHODS: The United Network for Organ Sharing registry was used to identify patients undergoing isolated heart transplantation between 1987 and 2020. Patients were stratified by the decade of transplantation. Overall survival was compared using Kaplan-Meier analysis, and risk-adjustment was performed using Cox proportional hazards modeling. RESULTS: A total of 76 009 heart transplantations occurred in the study period, including 20 352 female patients and 809 female patients with PPCM. The frequency of transplantation for PPCM increased over the study period (P = .015). Among female patients, PPCM was significantly associated with 1-year mortality compared with nonischemic cardiomyopathy (hazard ratio, 1.38; 95% CI, 1.11-1.69; P = .004). Among patients with PPCM, Black and Hispanic heart transplant recipients had increased 1-year posttransplant mortality risk compared with White recipients. On Kaplan-Meier survival analysis, early and midterm survival was significantly worse in patients with PPCM compared with other female patients. The 5-, 10-, and 15-year survivals in patients with PPCM were 66.5%, 49.0%, and 40.2% compared with 74.3%, 56.0%, and 37.5% in female heart transplant recipients with other heart failure diagnoses, respectively (P < .001). Survival improved significantly in patients who underwent heart transplantation for PPCM in the latest decade from 2010 to 2020 compared with earlier decades (P < .001), and this improvement was most marked for Black recipients. CONCLUSIONS: Patients who underwent heart transplantation for PPCM have a significantly elevated risk for 1-year mortality compared with other female transplant recipients. However, survival among these patients has improved in the last decade, particularly for Black transplant recipients.

Phenotypic characterization of primary cardiac fibroblasts from patients with HFpEF.

Heart failure is a leading cause of hospitalizations and mortality worldwide. Heart failure with a preserved ejection fraction (HFpEF) represents a significant clinical challenge due to the lack of available treatment modalities for patients diagnosed with HFpEF. One symptom of HFpEF is impaired diastolic function that is associated with increases in left ventricular stiffness. Increases in myocardial fibrillar collagen content is one factor contributing to increases in myocardial stiffness. Cardiac fibroblasts are the primary cell type that produce fibrillar collagen in the heart. However, relatively little is known regarding phenotypic changes in cardiac fibroblasts in HFpEF myocardium. In the current study, cardiac fibroblasts were established from left ventricular epicardial biopsies obtained from patients undergoing cardiovascular interventions and divided into three categories: Referent control, hypertension without a heart failure designation (HTN (-) HFpEF), and hypertension with heart failure (HTN (+) HFpEF). Biopsies were evaluated for cardiac myocyte cross-sectional area (CSA) and collagen volume fraction. Primary fibroblast cultures were assessed for differences in proliferation and protein expression of collagen I, Membrane Type 1-Matrix Metalloproteinase (MT1-MMP), and α smooth muscle actin (αSMA). Biopsies from HTN (-) HFpEF and HTN (+) HFpEF exhibited increases in myocyte CSA over referent control although only HTN (+) HFpEF exhibited significant increases in fibrillar collagen content. No significant changes in proliferation or αSMA was detected in HTN (-) HFpEF or HTN (+) HFpEF cultures versus referent control. Significant increases in production of collagen I was detected in HF (-) HFpEF fibroblasts, whereas significant decreases in MT1-MMP levels were measured in HTN (+) HFpEF cells. We conclude that epicardial biopsies provide a viable source for primary fibroblast cultures and that phenotypic differences are demonstrated by HTN (-) HFpEF and HTN (+) HFpEF cells versus referent control.

HVAD versus heartmate III bridge to heart transplantation: Waitlist and posttransplant outcomes.

BACKGROUND: This study compared outcomes of patients bridged with either the Heartware HVAD or Heartmate 3 (HM3) device to orthotopic heart transplantation (OHT). METHODS: The United Network of Organ Sharing registry was queried to perform two separate analyses of adult, isolated OHT candidates bridged with HVAD or HM3. First, waitlist outcomes were compared among patients waitlisted 1/1/2015-3/20/2020. Second, posttransplant survival was compared among those transplanted 1/1/2015-3/20/2020. RESULTS: Two thousand two hundred fifty-five candidates were waitlisted within the study period, 1587 (70.4%) bridged with HVAD and 668 (29.6%) with HM3. At 1 year from waitlisting, cumulative incidence of OHT higher in the HVAD cohort (p < .001). During the same time period, 2643 patients underwent OHT, 2154 (81.5%) with prior HVAD and 489 (18.5%) with HM3. Yearly proportions of patients bridged with HM3 increased across the study period and decreased for HVAD (p < .001). HM3-bridged recipients had shorter waitlist times, longer graft cold ischemic times, and experienced a higher rate of posttransplant dialysis requirement. Unadjusted and risk-adjusted posttransplant mortality rates were similar between both groups. CONCLUSIONS: Posttransplant survival is equivalent regardless of device type used for bridging. However, HM3 patients had lower likelihood of reaching transplantation, which may be a reflection of the recent heart allocation policy changes.

Hemodynamic Impact of MitraClip Procedure for Systemic Tricuspid Regurgitation in Congenitally Corrected Transposition of Great Arteries: A Case Report.

Patients with congenitally-corrected transposition of the great arteries (ccTGA) commonly develop significant systemic tricuspid valve regurgitation and systemic right ventricular dysfunction in adulthood, both of which presenting a therapeutic dilemma for the care team. Here we describe the case of a 35-year-old male with congenitally-corrected transposition of the great arteries who presented with severe systemic tricuspid valve regurgitation, biventricular systolic failure, and pulmonary hypertension. Due to prohibitive surgical risk, he underwent percutaneous tricuspid valve repair via MitraClip placement. Post-procedure, he demonstrated rapidly improved symptoms and sustained echocardiographic and hemodynamic evaluations. Few reports exist describing the safety and feasibility of the MitraClip procedure on a systemic tricuspid valve, but to our knowledge, this is the first to describe invasive hemodynamic improvements in patients with this degree of cardiopulmonary sequelae from the congenital lesion. There may be optimism for the MitraClip procedure as "bridge to list" in patients with ccTGA otherwise initially ineligible for surgical valve intervention or transplant.

Understanding Readmissions in Medicare Beneficiaries During the 90-Day Follow-Up Period of an Acute Myocardial Infarction Admission.

Background Medicare has a voluntary episodic payment model for Medicare beneficiaries that bundles payment for the index acute myocardial infarction (AMI) hospitalization and all post-discharge services for a 90-day follow-up period. The purpose of this study is to report on the types and frequency of readmissions and identify demographic and clinical factors associated with readmission of Medicare beneficiaries that survived their AMI hospitalization. Methods and Results This retrospective study used the Inpatient Standard Analytical File for 2014. There were 143 286 Medicare beneficiaries with AMI who were discharged alive from 3619 hospitals. All readmissions occurring in any hospital within 90 days of the index AMI discharge date were identified. Of 143 286 Medicare beneficiaries discharged alive from their index AMI hospitalization, 28% (40 145) experienced at least 1 readmission within 90 days and 8% (11 477) had >1 readmission. Readmission rates were higher among Medicare beneficiaries who did not undergo a percutaneous coronary intervention in their index AMI admission (34%) compared with those that underwent a percutaneous coronary intervention (20.2%). Using all Medicare beneficiary's index AMI, 27 comorbid conditions were significantly associated with the likelihood of a Medicare beneficiary having a readmission during the follow-up period. The strongest clinical characteristics associated with readmissions were dialysis dependence, type 1 diabetes mellitus, and heart failure. Conclusions This study provides benchmark information on the types of hospital readmissions Medicare beneficiaries experience during a 90-day AMI bundle. This paper also suggests that interventions are needed to alleviate the need for readmissions in high-risk populations, such as, those managed medically and those at risk of heart failure.

Impact of Complications on Resource Utilization During 90-Day Coronary Artery Bypass Graft Bundle for Medicare Beneficiaries.

BACKGROUND: The study reports the impact of adverse events during the index coronary artery bypass graft surgery (CABG) on Medicare reimbursement for the index hospitalization and a 90-day follow-up period. METHODS: This retrospective study used 2014 Medicare claims files for hospitals, skilled nursing services, rehabilitation facilities, long-term care facilities, home health services, and outpatient visits. The study sample is 37,106 Medicare beneficiaries that survived an index CABG in a US hospital during the first three quarters of 2014. Adverse events included acute renal failure, new onset hemodialysis, postoperative respiratory failure, any infection (postoperative infection, or sepsis), postoperative shock and hemorrhage, postoperative stroke, and reoperation during index hospitalization. RESULTS: Total average Medicare reimbursement for all services consumed during index CABG hospitalization and the 90-day postdischarge period was $42,063 ± $23,284. The index CABG hospitalization accounted for $32,544 ± $14,406, 77.4% of the bundle. Medicare beneficiaries having at least one adverse event had significantly higher total average Medicare reimbursement by $15,941 ($54,280 versus $38,339) for the bundle compared with Medicare beneficiaries not having an adverse event. The risk-adjusted incremental Medicare reimbursement for the entire 90-day bundle exceeded $20,000 for four adverse events: new-onset hemodialysis, $33,250; septicemia, $32,063; postoperative stroke, $24,117; and postoperative infection, $23,801. CONCLUSIONS: Medicare beneficiaries who have adverse events during their index CABG hospitalization will significantly affect that hospital's financial risk. The challenge under the voluntary CABG bundled payment program will be to monitor and reduce adverse events and manage the services consumed by Medicare beneficiaries having adverse events delivered at all the venues of care.

A propensity matched analysis of robotic, minimally invasive, and conventional mitral valve surgery.

OBJECTIVES: Institutional studies suggest robotic mitral surgery may be associated with superior outcomes. The objective of this study was to compare the outcomes of robotic, minimally invasive (mini), and conventional mitral surgery. METHODS: A total of 2300 patients undergoing non-emergent isolated mitral valve operations from 2011 to 2016 were extracted from a regional Society of Thoracic Surgeons database. Patients were stratified by approach: robotic (n=372), mini (n=576) and conventional sternotomy (n=1352). To account for preoperative differences, robotic cases were propensity score matched (1:1) to both conventional and mini approaches. RESULTS: The robotic cases were well matched to the conventional (n=314) and mini (n=295) cases with no significant baseline differences. Rates of mitral repair were high in the robotic and mini cohorts (91%), but significantly lower with conventional (76%, P<0.0001) despite similar rates of degenerative disease. All procedural times were longest in the robotic cohort, including operative time (224 vs 168 min conventional, 222 vs 180 min mini; all P<0.0001). The robotic approach had comparable outcomes to the conventional approach except there were fewer discharges to a facility (7% vs 15%, P=0.001) and 1 less day in the hospital (P<0.0001). However, compared with the mini approach, the robotic approach had more transfusions (15% vs 5%, P<0.0001), higher atrial fibrillation rates (26% vs 18%, P=0.01), and 1 day longer average hospital stay (P=0.02). CONCLUSION: Despite longer procedural times, robotic and mini patients had similar complication rates with higher repair rates and shorter length of stay metrics compared with conventional surgery. However, the robotic approach was associated with higher atrial fibrillation rates, more transfusions and longer postoperative stays compared with minimally invasive approach.

6-Minute walk test predicts prolonged hospitalization in patients undergoing transcatheter mitral valve repair by MitraClip.

BACKGROUND: The 6-minute walk test (6MWT) is a simple functional test that can predict exercise capacity and is widely employed to assess treatment outcomes. Although mortality with transcatheter mitral valve repair (TMVr) using the MitraClip (Abbott Vascular, Menlo Park, CA) is significantly less than for open mitral valve surgery in high-risk patients, identifying which patient will benefit the most from TMVr remains a concern. There are limited prognostic metrics guiding patient selection and, no studies have reported relationship between prolonged hospitalization and 6MWT. This study aimed to determine if the 6MWT can predict prolonged hospitalization in patients undergoing TMVr by MitraClip. METHODS: We retrospectively reviewed 162 patients undergoing 6MWT before TMVr. Patients were divided into three groups according to the 6MWT distance (6MWTD) using the median (6MWTD ≥219 m, 6MWTD <219 m, and Unable to Walk). Multivariate logistic regression model was applied to select the demographic characteristics that were associated with the prolonged hospitalization defined as total length of stay ≥4 days in the study. RESULTS: We found that 6MWT (odds ratio 3.64, 95% confidence interval 2.03-6.52, P < 0.001) was independently associated with prolonged hospitalization after adjustment in multivariate analysis. Area under the curve of 6MWT for predicting prolonged hospitalization was 0.79 (95% confidence interval 0.72-0.85). CONCLUSIONS: Our study demonstrates that 6MWT was independently associated with prolonged hospitalization in patients with TMVr, and has a good discriminatory performance for predicting prolonged hospitalization.

Trends in Aortic Valve Replacement Procedures Between 2009 and 2015: Has Transcatheter Aortic Valve Replacement Made a Difference?

BACKGROUND: This study reports trends in volume and adverse events associated with isolated aortic valve procedures performed in Medicare beneficiaries between 2009 and 2015. METHODS: This retrospective study used the annual fiscal year Medicare Provider Analysis and Review file to identify all Medicare beneficiaries undergoing an isolated aortic valve procedure. Outcome measures included three mortality rates and nine in-hospital adverse events. The final study population consisted of 233,660 hospitalizations. RESULTS: During the study period, Medicare beneficiaries undergoing an aortic valve procedure increased from 22,076 to 49,362, for an average annual growth rate of 14.45%. Transcatheter aortic valve replacement (TAVR) procedures per 100,000 Medicare beneficiaries grew from 10.7 in 2012 to 41.1 in 2015. Overall, in-hospital mortality rates, cumulative 30-day mortality rates, and 90-day postdischarge mortality rates declined annually during the study period. However, the 90-day mortality rate for TAVR was nearly double the rate for the tissue surgical aortic valve replacement group. Nearly 68% of Medicare beneficiaries experienced at least one in-hospital adverse event during their index hospitalization. Medicare beneficiaries undergoing TAVR had the lowest observed adverse events rates among the aortic valve procedures in 2015. CONCLUSIONS: The total number of Medicare beneficiaries undergoing isolated aortic valve procedures increased from 47.5 to 88.9 per 100,000 Medicare beneficiaries during the study period. Aortic valve procedures increased significantly during this study period primarily due to the increase in TAVR, with clinical outcomes improving as well. Although long-term outcomes of TAVR are still under investigation, these results are promising.

Predictive Value of Age-Adjusted Charlson Co-Morbidity Index for 1-, 3-, and 5-Year Mortality in Patients Requiring Transcatheter Mitral Valve Repair.

Co-morbidities increase markedly with aging, and they often negatively affect its prognosis. Although mortality with transcatheter mitral valve repair (TMVr) is significantly less than for open mitral valve surgery in patients at high surgical risk, it remains a concern to identify which patients will benefit from this treatment. Some prognostic metrics have been reported to guide better patient selection; however, universal risk stratification measures have not been established. This study aimed to determine if age-adjusted Charlson co-morbidity index (CCI) could predict mortality in patients who underwent TMVr and to assess its discriminatory performance in long-term outcomes. We retrospectively reviewed 222 patients who underwent TMVr, and 7 who died in hospital was excluded. Cox proportional hazard models were applied to select the demographic characteristics that were associated with cumulative mortality. Receiver-operating characteristic analyses were performed for predicting all-cause mortality, and discriminatory performance was assessed. We found that the age-adjusted CCI (hazard ratio 1.33, 95% confidence interval 1.16 to 1.51, p <0.001), New York Heart Association classification, and atrial fibrillation were independently associated with mortality. The age-adjusted CCI demonstrated good discriminative performance for predicting mortality at 3 and 5 years (area under the curve 0.71 and 0.77, respectively) and were greater than those of the Society of Thoracic Surgeons score in receiver-operating characteristic analysis. Kaplan-Meier curve demonstrated that the age-adjusted CCI ≥ 8 had poor prognosis after TMVr. In conclusions, the age-adjusted CCI could predict mortality and had a good discriminative performance for predicting longer term outcomes in patients who underwent TMVr.

Outcomes of patients implanted with a left ventricular assist device at nontransplant mechanical circulatory support centers.

The goal of this study was to assess outcomes of patients who underwent implantation of left ventricular assist devices (LVADs) at nontransplantation mechanical circulatory support centers. As the availability of LVADs for advanced heart failure has expanded to nontransplantation mechanical circulatory support centers, concerns have been expressed about maintaining good outcomes. Demographics and outcomes were evaluated in 276 patients with advanced heart failure who underwent implantation of LVADs as bridge to transplantation or destination therapy at 27 open-heart centers. Baseline characteristics, operative mortality, length of stay, readmission rate, adverse events, quality of life, and survival were analyzed. The overall 30-day mortality was 3% (8 of 276), and survival rates at 6, 12, and 24 months, respectively, were 92±2%, 88±3%, and 84±4% for the bridge-to-transplantation group and 81±3%, 70±5%, and 63±6% for the destination therapy group, comparable with results published by the national Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS). The median length of stay for all patients was 21 days. Bleeding was the most frequent adverse event. Stroke occurred in 4% (bridge to transplantation) and 6% (destination therapy) of patients. Quality-of-life measures and 6-minute walk distances showed sustained improvements throughout support. In conclusion, outcomes with LVAD support at open-heart centers are acceptable and comparable with results from the INTERMACS registry. With appropriate teams, training, center commitment, and certification, LVAD therapy is being disseminated in a responsible way to open-heart centers.

Totally endoscopic coronary artery bypass grafting on the arrested heart.

In the late 1990s, totally endoscopic coronary artery bypass grafting was successfully introduced into the heart surgery armamentarium using robotic techniques. Surgeons have applied the da Vinci telemanipulation system in order to develop completely endoscopic placement of internal mammary artery bypass grafts, mainly to the left anterior descending artery system. Multivessel procedures are currently under development. These operations can be carried out on the arrested heart using remote access perfusion and cardioplegic arrest via ascending aortic balloon occlusion. Another option is performing procedures on the beating heart using an endostablilizer and local coronary artery occlusion. In this review, the technique and specific aspects of the arrested heart version of totally endoscopic coronary artery bypass grafting are outlined.

Target vessel detection and coronary anastomosis assessment by intraoperative 12-MHz ultrasound.

PURPOSE: Our aim was to assess whether the left internal mammary artery, left anterior descending artery, and anastomosis could be visualized by intraoperative ultrasound for safe graft harvesting, optimal anastomotic target selection, and quality control. DESCRIPTION: In 10 patients, the left internal mammary artery, the left anterior descending artery, and the constructed anastomosis were scanned with 12-MHz epicardial ultrasound. Anastomosis quality was assessed on ultrasound and compared with surgeon score. EVALUATION: All left internal mammary arteries and left anterior descending arteries could be identified, and pathways could be followed on the ultrasound. Plaque and calcifications were detectable. Deviation from initial coronary anastomotic target was necessary in 2 of 10 patients. None of the constructed anastomoses needed revision. On the anastomotic scans, six anastomoses scored satisfactory and four scored good. CONCLUSIONS: Epicardial ultrasound was able to evaluate vessel characteristics and coronary anastomosis patency. This can lead to correction of surgical technique related problems in the operating room, possibly improving graft patency. Further advancements could make epicardial ultrasound a cost effective standard for anastomotic quality control. Applying it during robotic-assisted bypass surgery could make this procedure appropriate for more patients.

Integrated coronary revascularization: percutaneous coronary intervention plus robotic totally endoscopic coronary artery bypass.

BACKGROUND: Robotic totally endoscopic coronary artery bypass (TECAB) of the left anterior descending artery (LAD) coupled with percutaneous coronary intervention (PCI) of a second coronary artery has been investigated in patients with multivessel disease to provide a minimally invasive therapeutic option. METHODS AND RESULTS: TECAB of the LAD was performed using the left internal mammary artery (LIMA). A second lesion was treated with PCI before surgery, simultaneously, or after surgery. Three-month angiographic follow-up was performed in all patients and was subject to independent review. A total of 27 patients requiring double vessel revascularization were treated at 7 centers. Eleven patients underwent PCI before surgery, 12 patients underwent PCI after surgery, and 4 patients underwent simultaneous surgical and percutaneous intervention. Ten patients (37%) were treated with bare metal stents, whereas 17 patients (63%) were treated with drug-eluting stents. Postoperative angiographic evaluation demonstrated an overall LIMA anastomotic patency of 96.3% and PCI vessel patency of 66.7%. There were no deaths or strokes. One patient experienced a perioperative myocardial infarction. Eight of 27 patients (29.6%) required reintervention, 1 LIMA anastomotic stenosis (3.7%), 3 after bare metal stent (30%), and 4 after drug-eluting stent placement (23.5%). CONCLUSIONS: Integrated revascularization treatment plans provide minimally invasive options for patients with multivessel coronary artery disease. This approach may be accomplished with no mortality, low perioperative morbidity, and excellent angiographic LIMA patency. The reintervention rate after PCI in this series was higher than that reported elsewhere and should be investigated further. The choice of suitable vessel, type of stent and timing of the treatment must be carefully considered before implementing this hybrid strategy.