Temporary left ventricular assist devices as a bridge to heart transplantation

BACKGROUND

To create equitable access to donor organs for the highest mortality patients, the cardiac transplant allocation system now prioritizes patients with surgically implanted temporary left ventricular assist devices (T-LVADs). The outcomes following a direct bridge from a T-LVAD to orthotopic heart transplant (OHT) are not well delineated.

AIM

This study investigates the T-LVAD waitlist outcomes and compares the posttransplant outcomes in patients bridged to OHT with surgically implanted T-LVADs to patients bridged with durable continuous-flow left ventricular assist devices (CF-LVADs).

METHODS

Adults recorded in the United Network for Organ Sharing registry bridged to OHT with a durable CF-LVAD and T-LVADs, with or without temporary right ventricular assist devices (T-RVADs), between 2010 and 2018 were included. Propensity matching and multivariable Cox regression were utilized to compare outcomes.

RESULTS

Of 504 patients waitlisted with T-LVADs, the majority were transplanted (50%), bridged to CF-LVAD (17%), or recovered (9%). A total of 9047 recipients were bridged to OHT during the study period with 8875 CF-LVADs and 172 T-LVADs. Early survival in propensity-matched T-LVAD ± T-RVAD patients was similar to CF-LVAD ± T-RVAD patients but reduced at a 1-year follow-up. This difference in survival at 1-year follow-up was attributable to significantly reduced survival in patients with combined T-LVAD + T-RVAD support when compared with CF-LVAD, isolated T-LVAD and combined CF-LVAD + T-RVAD support (80% vs 90% vs 90% vs 91%; P = .005).

CONCLUSIONS

This study demonstrates that most patients waitlisted with a T-LVAD are successfully bridged to durable therapy or recover, and those bridged to OHT have acceptable posttransplant outcomes, particularly when T-RVADs are not required.

Outcomes From Transcatheter Aortic Valve Replacement in Patients With Low-Flow, Low-Gradient Aortic Stenosis and Left Ventricular Ejection Fraction Less Than 30%: A Substudy From the TOPAS-TAVI Registry

Importance

In low-flow, low-gradient aortic stenosis (LFLG AS), the severity of left ventricular dysfunction remains a key factor in the evaluation of aortic valve replacement.

Objective

To evaluate the clinical outcomes and changes in left ventricular ejection fraction (LVEF) after transcatheter aortic valve replacement (TAVR) in patients with LFLG AS and severe left ventricular dysfunction.

Design, Setting, and Participants

This multicenter registry is a substudy of the True or Pseudo-Severe Aortic Stenosis-TAVI registry that included patients with classic LFLG AS, defined as a mean transvalvular gradient less than 35 mm Hg, an effective orifice area less than 1.0 cm2, and an LVEF of 40% or less. Patients were divided in groups with very low (<30%) LVEF and low (30%-40%) LVEF. Dobutamine stress echocardiography (DSE) was performed before TAVR in a subset with very low LVEF, and presence of contractile reserve was defined as an increase of 20% or more in stroke volume. Clinical outcomes were assessed at 1 and 12 months and yearly thereafter, and echocardiography was performed at 1-year follow-up. Retrospective data were collected from 2007 to 2013 and prospective data from January 2013 to March 2018. Data were analyzed from March to October 2018.

Exposures

Transcatheter aortic valve replacement in patients with LFLG AS.

Main Outcomes and Measures

Changes in LVEF over time; periprocedural and late mortality.

Results

A total of 293 patients were included, including 128 (43.7%) with very low LVEF and 165 with low LVEF (56.3%). Their mean (SD) age was 80 (7) years, and most (214 [73.0%]) were men. The mean (SD) LVEF in the very low LVEF group was 22% (5%), compared with 37% (7%) in the low LVEF group (P < .001). There were no differences between groups in rates of periprocedural mortality and late mortality (median [interquartile range], 23 [6-38] months). Patients with very low LVEF displayed a greater increase in LVEF at the 1-year follow-up examination (mean absolute increase, 11.9% [95% CI, 8.8%-15.1%]), than the low LVEF group (3.6% [95% CI, 1.1%-6.1%]; P < .001). In 92 patients with very low LVEF who had preprocedural DSE, results showed a lack of contractile reserve in 45 (49%), but this had no effect on clinical outcomes or changes in LVEF over time.

Conclusions and Relevance

In patients with LFLG AS and severe left ventricular dysfunction, TAVR was associated with similar clinical outcomes as in counterparts with milder left ventricular dysfunction. The TAVR procedure was associated with a significant increase in LVEF, irrespective of contractile reserve. These results support TAVR for LFLG AS, irrespective of the severity of left ventricular dysfunction and DSE results.

Two-Year Outcomes After Transcatheter Aortic Valve Replacement With Mechanical vs Self-expanding Valves: The REPRISE III Randomized Clinical Trial

Importance

To our knowledge, REPRISE III is the first large randomized comparison of 2 different transcatheter aortic valve replacement platforms: the mechanically expanded Lotus valve (Boston Scientific) and self-expanding CoreValve (Medtronic).

Objective

To evaluate outcomes of Lotus vs CoreValve after 2 years.

Design, Setting, and Participants

A total of 912 patients with high/extreme risk and severe, symptomatic aortic stenosis enrolled between September 22, 2014, and December 24, 2015, were randomized 2:1 to receive Lotus (607 [66.6%]) or CoreValve (305 [33.4%] at 55 centers in North America, Europe, and Australia. The first 2-year visit occurred on October 17, 2016, and the last was conducted on April 12, 2018. Clinical and echocardiographic assessments are complete through 2 years and will continue annually through 5 years.

Main Outcomes and Measures

All-cause mortality and all-cause mortality or disabling stroke at 2 years. Other clinical factors included overall stroke, disabling stroke, repeated procedures, rehospitalization, valve thrombosis, and pacemaker implantation. Echocardiographic analyses included effective orifice area, mean gradient, and paravalvular leaks (PVLs).

Results

Of 912 participants, the mean (SD) age was 82.8 (7.3) years, 465 (51%) were women, and the mean (SD) Society of Thoracic Surgeons predicted risk of mortality was 6.8% (4.0%). At 2 years, all-cause death was 21.3% with Lotus vs 22.5% with CoreValve (hazard ratio [HR], 0.94; 95% CI, 0.69-1.26; P = .67) and all-cause mortality or disabling stroke was 22.8% with Lotus and 27.0% with CoreValve (HR, 0.81; 95% CI, 0.61-1.07; P = .14). Overall stroke was 8.4% vs 11.4% (HR, 0.75; 95% CI, 0.48-1.17; P = .21); disabling stroke was more frequent with CoreValve vs Lotus (4.7% Lotus vs 8.6% CoreValve; HR, 0.53; 95% CI, 0.31-0.93; P = .02). More Lotus patients received a new permanent pacemaker (41.7% vs 26.1%; HR, 1.87; 95% CI, 1.41-2.49; P < .01) or had a valve thrombosis (3.0% vs 0.0%; P < .01) compared with CoreValve. More patients who received CoreValve experienced a repeated procedure (0.6% Lotus vs 2.9% CoreValve; HR, 0.19; 95% CI, 0.05-0.70; P < .01), valve migration (0.0% vs 0.7%; P = .05), or embolization (0.0% vs 2.0%; P < .01) than Lotus. Valve areas remained significantly larger and the mean gradient was lower with CoreValve than Lotus (valve area, mean [SD]: Lotus, 1.53 [0.49] cm2 vs CoreValve, 1.76 [0.51] cm2; P < .01; valve gradient, mean [SD]: Lotus, 13.0 [6.7] mm Hg vs 8.1 [3.7] mm Hg; P < .01). Moderate or greater PVL was more frequent with CoreValve (0.3% Lotus vs 3.8% CoreValve; P < .01) at 2 years. Larger improvements in New York Heart Association (NYHA) functional class were observed with Lotus compared with CoreValve (improved by ≥1 NYHA class: Lotus, 338 of 402 [84.1%] vs CoreValve, 143 of 189 [75.7%]; P = .01; improved by ≥2 NYHA classes: 122 of 402 [37.3%] vs 65 of 305 [21.3%]).

Conclusions and Relevance

After 2 years, all-cause mortality rates, mortality or disabling stroke were similar between Lotus and CoreValve. Disabling stroke, functional class, valve migration, and PVL favored the Lotus arm whereas valve hemodynamics, thrombosis, and new pacemaker implantation favored the CoreValve arm.

Trial Registration

clinicaltrials.gov Identifier: NCT02202434.

Association of Structural and Functional Cardiac Changes With Transcatheter Aortic Valve Replacement Outcomes in Patients With Aortic Stenosis

Importance

Severe aortic stenosis causes pressure overload of the left ventricle, resulting in progressive cardiac dysfunction that can extend beyond the left ventricle. A staging system for aortic stenosis has been recently proposed that quantifies the extent of structural and functional cardiac changes in aortic stenosis.

Objectives

To confirm the reproducibility of a proposed staging system and expand the study findings by performing a survival analysis and to evaluate the association of aortic stenosis staging with both cardiac and noncardiac post-transcatheter aortic valve replacement (TAVR) readmissions.

Design, Setting, and Participants

A cohort analysis was conducted involving patients with severe aortic stenosis who underwent TAVR at the University of Pittsburgh Medical Center between July 1, 2011, and January 31, 2017. Patients who had undergone TAVR for valve-in-valve procedures and had an incomplete or unavailable baseline echocardiogram study for review were excluded. Clinical, laboratorial, and procedural data were collected from the Society of Thoracic Surgeons database and augmented by electronic medical record review.

Exposures

The aortic stenosis staging system is based on echocardiographic markers of abnormal cardiac function. The stages are as follows: stage 1 (left ventricle changes - increased left ventricular mass index; early mitral inflow to early diastolic mitral annulus velocity (E/e') >14; and left ventricular ejection fraction <50%), stage 2 (left atrial or mitral changes - left atrial volume index >34 mL/m2; moderate to severe mitral regurgitation; and atrial fibrillation), stage 3 (pulmonary artery or tricuspid changes - pulmonary artery systolic pressure ≥60 mm Hg; moderate to severe tricuspid regurgitation), and stage 4 (right ventricle changes - moderate to severe right ventricle dysfunction).

Main Outcomes and Measures

Primary outcome was post-TAVR all-cause mortality. Secondary outcomes were composite outcomes of all-cause mortality and post-TAVR all-cause and cardiac-cause readmissions.

Results

A total of 689 consecutive patients (351 [50.9%] were male, with a mean [SD] age of 82.4 [7.6] years) were included. The prevalence of stage 1 was 13%; stage 2, 62%; stage 3, 21%; and stage 4, 4%. Patients with higher staging had a greater burden of comorbidities as captured by the Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM). Despite adjustment for STS-PROM, a graded association was found between aortic stenosis staging and all-cause mortality (hazard ratio [HR] stage 2 vs stage 1: 1.37 [95% CI, 0.81-2.31; P = .25]; stage 3 vs stage 1: 2.24 [95% CI, 1.28-3.92; P = .005]; and stage 4 vs stage 1: 2.83 [95% CI, 1.39-5.76; P = .004]). Stage 3 patients had higher post-TAVR readmission rates for both cardiac (HR, 1.84; 95% CI, 1.13-3.00; P = .01) and noncardiac causes.

Conclusions and Relevance

Aortic stenosis staging appears to show a strong graded association between the extent of cardiac changes and post-TAVR all-cause mortality; such staging may improve patient care, risk stratification, assessment of prognosis, and shared decision making for patients undergoing TAVR.

Outcomes of Adult Heart Transplantation Using Hepatitis C-Positive Donors

Background

This study evaluated the impact of hepatitis C–positive (HCV+) donors on outcomes of heart transplantation in the United States.

Methods and Results

Adults undergoing isolated heart transplantation in the United States between January 1, 2016, and December 31, 2018, were included. The primary outcome was 1‐year post‐transplant survival. Multivariable Cox regression and 2:1 propensity matching were used to compare outcomes between transplants with HCV+ and hepatitis C–negative (HCV−) donors. A subanalysis was performed to evaluate the impact of nucleic acid amplification test positivity on outcomes. Of 7889 isolated heart transplants performed during the study period, 343 (4.4%) used HCV+ donors. Overall unadjusted 1‐year posttransplant survival was not statistically different between HCV− versus HCV+ donors (91.1% versus 90.2%; P=0.86), a finding that persisted after risk adjustment (hazard ratio, 1.05; 95% CI, 0.70–1.58; P=0.80). Propensity matching resulted in 675 well‐balanced patients (437 HCV− and 238 HCV+). Overall 1‐year posttransplant survival was not statistically different in propensity‐matched analysis (89.8% HCV− versus 89.2% HCV+; P=0.88). Rates of 1‐year drug‐treated rejection (21.1% versus 22.1%; P=0.84), postoperative dialysis (11.4% versus 14.7%; P=0.22), and stroke (4.6% versus 2.1%; P=0.10) were also not statistically different between HCV− and HCV+ groups, respectively. Outcomes were not statistically different between nucleic acid amplification test–negative and nucleic acid amplification test–positive HCV+ donors.

Conclusions

Adult heart transplants using HCV+ donors, including those that are nucleic acid amplification test positive, can be performed without an adverse impact on 1‐year survival. Wider implementation of protocols for using HCV+ donors and an assessment of longer‐term outcomes including seroconversion rates will be important in maximizing the effect of HCV+ donors on national donor shortages.

The Impact of Major Postoperative Complications on Long-Term Survival After Cardiac Surgery

BACKGROUND

This study evaluated the impact of postoperative complications on long-term survival after cardiac surgery.

METHODS

Adults undergoing an index cardiac operation from January 2010 to December 2017 were included. Patients were stratified by the number and type of major complications as defined by The Society of Thoracic Surgeons. Failure to rescue was defined as mortality after a complication that occurred before hospital discharge. Long-term mortality among patients with complications was defined as a postcomplication death occurring after hospital discharge. Multivariable Cox regression was used for risk adjustment.

RESULTS

In all, 9532 patients were included in the study, and 16.8% (n = 1600) had a major postoperative complication. Operative mortality was 0.8% for patients with no complications. Early failure to rescue increased as the number of complications increased (7.5%, 28.1%, and 51.5% for one, two, and three or more complications, respectively; P < .0001). Median length of intensive care unit and hospital stay ranged, respectively, from 38 hours and 7 days for patients with no complications to 359 hours and 23 days for patients with three or more complications (P < .0001). The adverse impact of complications on survival persisted at 1-year follow-up (3.5%, 18.8%, 52.1%, and 77.9%; P < .0001) and 5-year follow-up (10.8%, 33%, 61.8%, and 77.9%; P < .0001) for patients with no complications or one, two, or three or more complications, respectively. Risk-adjusted analysis confirmed these findings (P < .0001). Furthermore, 5-year survival conditional on 30-day survival ranged from 85.1% to 41.5% for patients with no complications versus three or more complications (P < .0001).

CONCLUSIONS

Postoperative complications after cardiac surgery, particularly when occurring in combination, have a profound impact on long-term survival, even after excluding early postoperative deaths.

Infective endocarditis: trends, surgical outcomes, and controversies

The number of hospitalizations and surgical cases of infective endocarditis (IE) are increasing. The aim of this study was to review these trends, surgical outcomes, and controversies related to IE. A search of MEDLINE of studies published between 1960 and 2018 was conducted. Search terms included "infective endocarditis", "history of", "trend", "epidemiology", "outcome", "medical management", "surgery", "indication", and "re-operative surgery", or any combination thereof. The United States has the highest incidence of IE in the world at 15 per 100,000 people, with increases in incidence due to the aging population as well as increasing rates of intravenous drug use (IVDU). National guidelines support early surgical intervention in specific clinical settings in both left and right-sided IE. However, only 11% of the evidence used in formulating guidelines for surgical therapy in IE are based on level A evidence. Ongoing controversies include whether to perform surgery in the setting of continued or recurrent IVDU in a patient with a prior valve operation, timing of surgery after acute stroke due to IE, and general indications for surgery for tricuspid valve IE. IE has a surging incidence and increasing burden on the healthcare system in the United States. Multiple controversies exist, and formulating level A evidence and multidisciplinary collaboration will be essential components to effectively treating this complex patient population.

Transcatheter Aortic Valve Replacement After Prior Mitral Valve Surgery: Results From the Transcatheter Valve Therapy Registry

BACKGROUND

Due to perceived technical challenges, patients with previous surgical mitral valve repair or replacement (SMVR) have been excluded from most transcatheter aortic valve replacement (TAVR) trials. Our objective was to compare the 30-day and 1-year outcomes of TAVR for patients with and without prior SMVR.

METHODS

In a retrospective review of The Society of Thoracic Surgeons (STS) and American College of Cardiology (ACC) Transcatheter Valve Therapy (TVT) Registry, we compared 1097 patients with prior SMVR to 46,327 patients without prior SMVR who underwent TAVR between November 2011 and September 2015 at 394 US centers. Preoperative characteristics, procedural details, and clinical outcomes were analyzed.

RESULTS

Patients with previous SMVR were younger, more often female, and had higher STS predicted risk of mortality (8.6% vs 6.8%, P < .001). However, there was no difference in 30-day mortality (4.6% vs 5.5%, P = .293), myocardial infarction, stroke, reintervention, new dialysis, or readmission. Moderate/severe paravalvular leak at discharge was also similar (5.8% vs 4.9%, P = .343). At 1 year, morbidity was similar with slightly higher mortality among patients with prior SMVR (20% vs 17.5%, P = .087) that was significant after adjustment (hazard ratio 1.18, P = .043). The type of prior SMVR (repair, bioprosthetic replacement, or mechanical replacement) had no impact on 30-day or 1-year survival.

CONCLUSIONS

Patients with prior SMVR undergoing TAVR had similar 30-day outcomes, slightly higher 1-year mortality, and no increase in early paravalvular leak compared with patients who did not have previous SMVR. Prior SMVR should not preclude TAVR for appropriately selected patients.

The impact of centre volume on outcomes of orthotopic heart transplant in older recipients

OBJECTIVES

The aim of this study was to evaluate the impact of overall and older-recipient-specific centre volumes on outcomes of orthotopic heart transplant (OHT) in older recipients.

METHODS

Patients aged ≥60 years undergoing OHT were identified in the United Network for Organ Sharing (UNOS) registry. The primary outcome was 1-year post-OHT mortality. Secondary outcomes included the incidence and impact on 1-year survival of postoperative complications including infection, renal failure requiring dialysis and stroke. Patients were divided into equal size tertiles based on overall and older-recipient-specific OHT centre volumes.

RESULTS

A total of 5373 older recipients were identified. Mean overall and older-recipient-specific volumes were 27.5 ± 19.5 and 9.4 ± 7.3 OHT/year, respectively. Although overall and older-recipient-specific low-volume centres were at higher risk of mortality in separate multivariable analysis, only older-recipient-specific volume contributed significantly to post-OHT mortality in the combined multivariable analysis (P < 0.05). In the receiver operating characteristic analysis, an older-recipient-specific volume of 8 OHTs/year was identified as the most discriminative volume threshold for mortality (area under the receiver operating characteristic curve = 0.68). Although low older-recipient-specific volume centres did not have significantly higher incidences of postoperative complications, they had significantly worse 1-year survival rates compared to higher volume centres in patients with postoperative infection or dialysis (each P < 0.01).

CONCLUSIONS

This large-cohort analysis demonstrates that older-recipient-specific centre volume contributes to post-OHT outcomes in the older recipients more significantly than overall volume. This may be a consequence of higher older-recipient-specific volume centres to better manage specific complications in this patient population.