Impact of Myocardial Viability on Long-term Outcomes after Surgical Revascularization.

BACKGROUND: This study was conducted to evaluate whether myocardial viability assessed with cardiac magnetic resonance (CMR) affected long-term clinical outcomes after coronary artery bypass grafting (CABG) in patients with ischemic cardiomyopathy (ICMP). METHODS: Preoperative CMR with late gadolinium enhancement (LGE) was performed in 103 patients (64.9 ± 10.1 years, male:female = 82:21) with 3-vessel disease and left ventricular dysfunction (ejection fraction ≤ 0.35). Transmural extent of LGE was evaluated on a 16-segment model, and transmurality was graded on a 5-point scale: grades-0, absence; 1, 1 to 25%; 2, 26 to 50%; 3, 51 to 75%; 4, 76 to 100%. Median follow-up duration was 65.5 months (interquartile range = 27.5-95.3 months). Primary endpoint was the composite of all-cause mortality or hospitalization for congestive heart failure. RESULTS: Operative mortality was 1.9%. During the follow-up, all-cause mortality and readmission for congestive heart failure occurred in 29 and 8 patients, respectively. The cumulative incidence of the primary endpoint was 31.3 and 46.8% at 5 and 10 years, respectively. Multivariable analysis demonstrated that the number of segments with LGE grade 4 was a significant risk factor (hazard ratio 1.42, 95% confidence interval 1.10-1.83, p = 0.007) for the primary endpoint among the variables assessed by CMR. Other risk factors included age, dialysis, chronic obstructive pulmonary disease, and EuroSCORE II. CONCLUSION: The number of myocardial segments with transmurality of LGE >75% might be a prognostic factor associated with the composite of all-cause mortality or hospitalization for congestive heart failure after CABG in patients with 3-vessel disease and ICMP.

Differences in Brain Metabolite Profiles Between Normothermia and Hypothermia.

BACKGROUND: This study evaluated the difference in brain metabolite profiles between normothermia and hypothermia reaching 25°C in humans in vivo. METHODS: Thirteen patients who underwent thoracic aorta surgery under moderate hypothermia were prospectively enrolled. Plasma samples were collected simultaneously from the arteries and veins to estimate metabolite uptake or release. Targeted metabolomics based on liquid chromatographic mass spectrometry and direct flow injection were performed, and changes in the profiles of respective metabolites from normothermia to hypothermia were compared. The ratios of metabolite concentrations in venous blood samples to those in arterial blood samples (V/A ratios) were calculated, and log2 transformation of the ratios [log2(V/A)] was performed for comparison between the temperature groups. RESULTS: Targeted metabolomics were performed for 140 metabolites, including 20 amino acids, 13 biogenic amines, 10 acylcarnitines, 82 glycerophospholipids, 14 sphingomyelins, and 1 hexose. Of the 140 metabolites analyzed, 137 metabolites were released from the brain in normothermia, and the release of 132 of these 137 metabolites was decreased in hypothermia. Two metabolites (dopamine and hexose) showed constant release from the brain in hypothermia, and 3 metabolites (2 glycophospholipids and 1 sphingomyelin) showed conversion from release to uptake in hypothermia. Glutamic acid demonstrated a distinct brain metabolism in that it was taken up by the brain in normothermia, and the uptake was increased in hypothermia. CONCLUSION: Targeted metabolomics demonstrated various degrees of changes in the release of metabolites by the hypothermic brain. The release of most metabolites was decreased in hypothermia, whereas glutamic acid showed a distinct brain metabolism.

Rapid-Deployment Aortic Valve Replacement in a Real-World All-Comers Population.

BACKGROUND: This study was conducted to evaluate the mid-term outcomes of rapid-deployment aortic valve replacement (AVR) using Edwards Intuity. METHODS: A total of 215 patients underwent rapid-deployment AVR using Edwards Intuity at our institution. The median follow-up duration was 22 months (interquartile range, 8-36). Primary outcomes were overall survival, cumulative incidence of cardiac death, and major adverse cardiac events. Secondary outcomes were early and 1-year hemodynamic performances of the bioprosthetic valve. RESULTS: The mean age was 68.6 ± 10.5 years, and EuroSCORE II was 3.09 ± 4.5. The study population included 113 patients (52.6%) with bicuspid valves (24 patients with type 0 bicuspid valves), 20 patients (9.3%) with pure aortic regurgitation, and 3 patients (1.4%) with infective endocarditis. Isolated AVR was performed in 70 patients (32.4%) and concomitant procedures were performed in 146 patients (67.6%), including aorta surgery (42.3%) and mitral valve procedure (22.3%). Operative mortality was 2.8%. Complete atrioventricular block occurred in 12 patients, but most of them were transient and only 3 patients received permanent pacemaker implantation before discharge. Overall survival at 3 years was 92.3%. Early hemodynamic data showed mean pressure gradients of 15.5 ± 5.0 and 12.7 ± 4.2 mm Hg in the 19 and 21 mm valve, respectively. One-year hemodynamics were also excellent with mean pressure gradients of 14.7 ± 5.3 and 10.7 ± 3.6 mm Hg in the 19 and 21 mm valve, respectively. CONCLUSION: Based on a real-world all-comers population, rapid-deployment AVR using Edwards Intuity could be performed for various indications, including bicuspid valve, pure aortic regurgitation, and infective endocarditis, and the clinical and hemodynamic outcomes were excellent.

Preliminary Report from a Randomized Controlled Trial Comparing Two Bovine Pericardial Valves.

BACKGROUND: A randomized controlled trial was designed to compare 1-year hemodynamic profiles and clinical outcomes after bioprosthetic aortic valve replacement (AVR) using a recently introduced (study group) and world-widely used (control group) bovine pericardial bioprostheses. This study evaluated early postoperative outcomes as a preliminary analysis. METHODS: The primary end point of the trial was the mean pressure gradient across the aortic valve (AVMPG) at 1 year after surgery. Patients were screened to enroll 70 patients in each group based on a noninferiority design. Early postoperative hemodynamic and clinical outcomes were compared between the two groups. RESULTS: There were no differences in baseline characteristics, including sex and body surface area (1.64 ± 0.18 vs. 1.65 ± 0.15 m2) between the two groups. The AVMPG on early postoperative echocardiography was 15.2 ± 4.6 mm Hg and 16.5 ± 6.2 mm Hg in the study and control groups, respectively (p = 0.177). Although AVMPG of the 19 mm prostheses was lower in the study group than in the control group (17.0 ± 6.3 mm Hg vs. 22.8 ± 6.6 mm Hg, p = 0.039), there were no significant differences in the effective orifice area in all patients (1.57 ± 0.41 cm2 vs. 1.53 ± 0.34 cm2, p = 0.568), and each valve size. The effective orifice area index was also similar between the two groups in overall (p = 0.352), and in each valve size. There were no significant differences in clinical outcomes including operative mortality and postoperative complications between the two groups. CONCLUSION: Early postoperative hemodynamic and clinical results after AVR using a recently introduced bovine pericardial valve were comparable with those using the control valve (NCT03796442).

Results after Tricuspid Valve Surgery for Preserved and Dysfunctional Right Ventricle.

BACKGROUND: This study aimed to compare long-term outcomes after tricuspid valve (TV) repair (TVr) with those after TV replacement (TVR) by adjusting the right ventricular (RV) volume and function. METHODS: We enrolled 147 patients who underwent TVr (n = 78) and TVR (n = 69) for grade 3 or 4 tricuspid regurgitation and had preoperative cardiac magnetic resonance data. Long-term clinical outcomes were compared between the two groups using inverse probability treatment weighting (IPTW) to adjust for differences in preoperative characteristics between the two groups. Subgroup analyses were performed in patients with preserved and dysfunctional RV (ejection fraction < 50%). RESULTS: There were no significant differences in operative mortality or postoperative complications between the two groups before and after the IPTW adjustment. Five- and 10-year overall survival rates were 84.2 and 67.1%, respectively. Five- and 10-year cumulative incidences of TV-related events (TVREs) were 33.1 and 55.6%, respectively. There were no significant differences in overall survival and cumulative incidence of TVREs after IPTW adjustment (p = 0.236 and p = 0.989, respectively). The risk-adjusted overall survival was marginally higher in the TVr group of patients with preserved RV function (p = 0.054), while no such significant difference was found between the two groups of patients with dysfunctional RV (p = 0.513). CONCLUSION: Adjusted long-term clinical outcomes after TVr and TVR were comparable. TVr might be beneficial for patients with preserved RV function in terms of long-term survival; however, this benefit might disappear in patients with RV dysfunction.

A Controlled Trial Comparing One-Year Hemodynamics of Two Bovine Pericardial Valves.

BACKGROUND: This randomized controlled trial was designed to compare 1-year hemodynamic performances and clinical outcomes after aortic valve replacement (AVR) using a recently introduced (the AVALUS group) and worldwide used (the CEPME group) bovine pericardial bioprostheses. METHODS: Patients were screened to enroll 70 patients in each group based on a noninferiority design. The primary endpoint of the trial was the mean pressure gradient across the aortic valve (AVMPG) at 1 year after surgery. One-year echocardiographic data were obtained from 92.1% (129 of 140 patients) of the study patients. RESULTS: There were no differences in baseline characteristics, including sex and body surface area (1.64 ± 0.18 vs. 1.65 ± 0.15 m2) between the groups. The AVMPG on 1-year echocardiography was 14.0 ± 4.3 and 13.9 ± 5.1 mmHg in the AVALUS and CEPME groups, respectively (the p-value for noninferiority was 0.0004). In the subgroup analyses for the respective size of the prostheses, AVMPG of the 19-mm prostheses was significantly lower in the AVALUS group than in the CEPME group (14.0 ± 4.3 vs. 20.0 ± 4.7 mmHg, p = 0.012), whereas those of the other sizes were not significantly different between the two groups. There were no significant differences in the effective orifice area (1.49 ± 0.40 vs. 1.53 ± 0.38 cm2, p = 0.500) or effective orifice area index (0.91 ± 0.22 vs 0.93 ± 0.23 cm2/m2, p = 0.570) in all the patients, or in the subgroup analysis for the 19-mm prosthesis. There were no differences in the 1-year clinical outcomes between the two groups. CONCLUSION: The 1-year hemodynamic and clinical outcomes of the AVALUS group were noninferior to those of the CEPME group (NCT03796442).

Aortic Valve Replacement in the Era of Transcatheter Aortic Valve Implantation: Current Status in Korea.

BACKGROUND: In the era of transcatheter aortic valve implantation, this study was conducted to investigate the current trend of aortic valve procedures in Korea and to evaluate the early and mid-term outcomes of isolated surgical aortic valve replacement (SAVR) using bioprosthetic valves in contemporary Korea. METHODS: Contemporary outcomes of isolated bioprosthetic SAVR in Korea were analyzed using the datasets on a multicenter basis. Patients who underwent isolated SAVR using bioprostheses from June 2015 to May 2019 were included, and those with concomitant cardiac procedures, SAVR with mechanical valve, or SAVR for infective endocarditis were excluded. A total of 456 patients from 4 large-volume centers were enrolled in this study. Median follow-up duration was 43.4 months. Early postoperative outcomes, mid-term clinical outcomes, and echocardiographic outcomes were evaluated. RESULTS: Mean age of the patients was 73.1 ± 7.3 years, and EuroSCORE II was 2.23 ± 2.09. The cardiopulmonary bypass time and aortic cross-clamp times were median 106 and 76 minutes, respectively. SAVR was performed with full median sternotomy (81.8%), right thoracotomy (14.7%), or partial sternotomy (3.5%). Operative mortality was 1.8%. The incidences of stroke and permanent pacemaker implantation were 1.1% and 1.1%, respectively. Paravalvular regurgitation ≥ mild was detected in 2.6% of the patients. Cumulative incidence of all-cause mortality at 5 years was 13.0%. Cumulative incidences of cardiovascular mortality and bioprosthetic valve dysfunction at 5 years were 7.6% and 6.8%, respectively. CONCLUSION: The most recent data for isolated SAVR using bioprostheses in Korea resulted in excellent early and mid-term outcomes in a multicenter study.

Incidence and Risk Factors of Pannus after Mechanical Aortic Valve Replacement.

BACKGROUND: This study was conducted to evaluate the occurrence rate and risk factors of subaortic pannus (SAP) after bileaflet mechanical aortic valve (AV) replacement. METHODS: Between 1990 and 2014, 862 patients underwent primary AV replacement with bileaflet mechanical prosthesis. SAP was defined as (1) gradual increase in mean pressure gradient through mechanical AV without any evidence of motion limitation of the leaflets on echocardiography and (2) AV mean pressure gradient >40 mm Hg or AV peak velocity >4 m/s on echocardiography, and (3) any visible subaortic tissue ingrowth beneath the mechanical AV on echocardiography or computed tomography. Clinical and echocardiographic follow-up durations were 13.8 ± 8.0 and 10.7 ± 7.9 years, respectively. RESULTS: Mean age was 51.1 ± 12.1 years and concomitant surgeries were performed in 503 patients (58.4%). Overall survival at 10 and 20 years was 84.2 and 67.1%, respectively. SAP occurred in 33 patients, and in only 2 patients during the first 10 years after surgery. The cumulative incidence of SAP formation at 10, 20, and 25 years were 0.3, 5.0, and 9.9%, respectively. The Fine and Gray model demonstrated that small prosthetic valve size (hazard ratio [HR] [95% confidence interval, CI] = 0.738 [0.575-0.946]), young age (HR [95% CI] = 0.944 [0.909-0.981]), and concomitant mitral valve replacement (MVR) (HR [95% CI] = 3.863 [1.358-10.988]) were significant risk factors for the SAP formation. CONCLUSIONS: SAP occurred gradually over time with 10- and 20-year cumulative incidence of 0.3 and 5.0%, respectively. Young age, small prosthetic valve size, and concomitant MVR were risk factors for SAP formation. Therefore, we recommend efforts to select large prostheses for young patients requiring concomitant MVR.

Long-Term Clinical Outcomes of the On-X Mechanical Prosthetic Valve in the Aortic or Mitral Position　- A Single-Center Experience of up to 20 Years' Follow up.

BACKGROUND: This study evaluated the long-term outcomes for up to 20 years after On-X mechanical valve implantation in the left side of the heart.Methods and Results:Between 1999 and 2015, 861 patients (mean age=51.6±10.9 years) who underwent prosthetic valve replacement using the On-X valve in the aortic or mitral position were enrolled (aortic=344, mitral=325, double=192). The mean clinical follow-up duration was 10.5±5.3 (median 10.9) years. Operative mortality occurred in 26 patients (3.0%), and linearized late cardiac mortality was 0.9%/patient-year without an intergroup difference. Linearized thromboembolism, bleeding, prosthetic valve endocarditis, non-structural valve deterioration (NSVD), and reoperation rates were 0.8%/patient-year, 0.6%/patient-year, 0.2%/patient-year, 0.5%/patient-year, and 0.5%/patient-year, respectively. Prosthetic valve endocarditis was more frequent after double valve replacement than after aortic or mitral valve replacement (P=0.008 and 0.005, respectively). NSVD and reoperation rates were significantly lower aortic valve replacement than after mitral or double valve replacement (P=0.001 and 0.002, P=0.001 and <0.001, respectively). Valve replacement in the mitral position was the only risk factor for NSVD (hazard ratio [95% confidence interval]=5.247 [1.608-17.116], P=0.006). CONCLUSIONS: On-X valve implantation in the left side heart had favorable clinical outcomes with acceptable early and late mortality and a low incidence of prosthetic valve-related complications. Particularly in the aortic position, the On-X valve had better long-term non-structural durability.

Comparative analysis of structural valve deterioration after bioprosthetic tricuspid valve replacement: Bovine pericardial versus porcine valves.

This study was conducted to compare the occurrence and the risk factors of structural valve deterioration (SVD) after bioprosthetic tricuspid valve replacement (TVR) between bovine pericardial valves and porcine valves. One-hundred and thirty-four TVR patients were enrolled; 108 patients underwent TVR with bovine pericardial bioprostheses (BTVR group) and 26 underwent TVR with porcine bioprostheses (PTVR group). The early results and long-term clinical outcomes were compared. The median follow-up duration was 90 (interquartile range: 33-135) months. Propensity score (PS) adjusted Cox regression and competing risk analyses were performed. The mean ages of the BTVR and PTVR groups were 62.2 ± 10.7 and 57.3 ± 13.9 years, respectively. The overall survival and cumulative incidence of cardiac death in the BTVR group were similar to those in the PTVR group (hazard ratio [95% confidence interval] = 1.399 [0.500-3.922] and 0.742 [0.249-2.212], respectively). SVD was significantly more frequent in the BTVR group (17.544 [1.070-243.902], P = .045). The tricuspid valve reoperation rate was significantly higher in the BTVR group (38.462 [2.591-476.190], P = .008). The cumulative incidence of SVD after bioprosthetic TVR was higher when using bovine pericardial valves than when using porcine valves.

Impact of Prosthesis-Patient Mismatch on Survival after Mitral Valve Replacement: A Meta-analysis.

BACKGROUND: Numerous studies have demonstrated a negative impact of prosthesis-patient mismatch (PPM) on long-term clinical outcomes after aortic valve replacement. However, the impact of PPM after mitral valve replacement (MVR) on clinical outcomes is still controversial. This study was conducted to evaluate the impact of PPM on early and long-term survival after MVR. METHODS: A literature search of five databases was performed. The primary and secondary outcomes were all-cause mortality and early mortality, respectively. Subgroup analyses were performed according to the risk of bias, patients' age, proportion of female patients, and proportion of patients with mechanical MVR. RESULTS: Eleven nonrandomized studies including 8,072 patients were included in this meta-analysis. The overall incidence of PPM was 58.0% (range: 10.4-85.9%). The odds ratio of early mortality in nine studies was not significantly different between the PPM and non-PPM patients (odds ratio: 1.35; 95% confidence interval [CI]: 0.98-1.86). A pooled analysis in 11 studies demonstrated that all-cause mortality after MVR was higher in the PPM than non-PPM patients (hazard ratio [HR]: 1.39; 95% CI: 1.09-1.77). This analysis revealed a moderate to high heterogeneity (I 2 = 69.4%). When pooled analyses were performed in two subgroups according to the proportion of patients with mechanical MVR, there were low heterogeneity in each group. No other subgroup analyses demonstrated a significant difference in the HR of all-cause mortality. Funnel plots and Egger's tests showed no visually and statistically significant publication bias. CONCLUSION: The present meta-analysis indicates that PPM negatively affects long-term survival after MVR.

Competitive Flow of Terminal Anastomosis to Right Coronary Territory in "Y" Coronary Artery Bypass.

BACKGROUND: We evaluated the prevalence and outcomes of competitive flow in the terminal right coronary artery (RCA) graft after coronary artery bypass grafting (CABG) with left internal thoracic artery-based Y-composite grafting at 1 year after CABG. METHODS: We enrolled 642 patients who underwent Y-composite graft-based off-pump CABG with in situ left internal thoracic artery between 2014 and 2022. All patients underwent early postoperative angiography, and 1-year postoperative angiography was performed in 81.2% (522/642) of patients. RESULTS: The early occlusion rate of distal anastomoses with Y-composite graft was 2.1%. Competitive flow was observed in 69 of 642 anastomoses (10.7%). Multivariate analysis showed that the maximal degree of target vessel stenosis (odds ratio [OR], 0.909; 95% CI, 0.886-0.931; P < .001), maximal degree of non-terminal target vessel in Y-arm grafts (OR, 1.103; 95% CI, 1.047-1.172; P < .001), and diabetes mellitus (OR, 0.535; 95% CI, 0.303-0.934; P = .029) were factors associated with competitive flow to the RCA territory. The optimal cutoff value for the degree of terminal target vessel stenosis predicting competitive flow to the RCA territory was 92.5%. The 1-year graft failure rate of anastomoses with competitive flow of the terminal anastomosis was 30.9% (17/55). The presence of competitive flow on early angiography was the only factor associated with graft occlusion of the terminal anastomosis at 1 year (OR, 2.339; 95% CI, 1.165-4.481; P = .013). CONCLUSIONS: For terminal anastomosis to the RCA territory in Y-composite graft-based CABG, the presence of competitive flow on early angiography was associated with graft occlusion of the terminal anastomosis at 1 year. Notably, 30.9% of these grafts demonstrated failure on 1-year follow-up angiography.

The impact of perivascular tissue preservation on 5-year patency of saphenous vein composite grafts.

OBJECTIVES: This retrospective study was conducted to evaluate the impact of saphenous vein (SV) harvesting with versus without perivascular tissue on the 5-year angiographic patency in coronary artery bypass grafting. METHODS: Among the 944 patients who received coronary artery bypass grafting between 2010 and 2015, 579 patients who received off-pump coronary artery bypass grafting using 1 SV as a Y-composite graft based on the in situ left internal thoracic artery were enrolled. SV harvesting was performed using no-touch technique without perivascular tissue (the NoPVT group) in 342 patients and with perivascular tissue (the PVT group) in 237 patients. Follow-up duration was 84.0 months (interquartile range 66.5-105.4). Propensity score matching was performed, and long-term clinical outcomes and angiographic patency were compared. RESULTS: The average number of distal anastomoses per patient was comparable between the groups, although more SV grafts were anastomosed to left anterior descending territory in the PVT group than in the NoPVT group. Overall survival and cumulative incidence of cardiac death were comparable between the groups, whereas cumulative incidence of target vessel revascularization (1.3% vs 4.3% at 5 year, P = 0.009) and that of major adverse cardiac events (7.3% vs 9.9% at 5 year, P = 0.035) were lower in the PVT group than in the NoPVT group. One-year and 5-year angiographic patency rates of the SV grafts were higher in the PVT group than in the NoPVT group [97.0% vs 91.7% (P = 0.004) and 96.3% vs 89.9% (P = 0.007), respectively]. CONCLUSIONS: SV grafts harvested using no-touch technique with perivascular tissue further improved the 5-year patency of SV composite grafts compared with those without perivascular tissue.

Early and mid-term outcomes of tricuspid valve surgery in patients with functional tricuspid regurgitation induced by atrial fibrillation.

Background: The strategy of treatment for tricuspid regurgitation (TR) induced by atrial fibrillation (AF) has not been established. The aim of this study was to evaluate the outcomes of surgical treatment for TR induced by AF. Methods: From 2000 to 2021, a total of 1,301 patients underwent tricuspid valve (TV) surgery. Among them 43 patients who diagnosed as AF induced TR were enrolled. The tricuspid valve-related events (TVRE) included cardiac death, TV reoperation, development of moderate or greater TV disease, congestive heart failure requiring re-admission, and major bleeding or thrombosis. The median follow-up duration was 42.0 months. Results: The interval from diagnosis of AF to more than moderate TR was 61.2 months, and the interval from initial diagnosis of severe TR to surgery was 2.4 months. Concomitant Cox-maze III procedure was performed in 39 patients. The operative mortality occurred in 1 patient, and there was no permanent pacemaker implantation. Overall survival rates at 1- and 5-year were 90.6% and 79.3%, respectively. The cumulative incidence of TVRE at 1- and 5-year were 16.3% and 26.5%, respectively. The cumulative incidences of AF recurrence at 1- and 3-year in the patients with surgical ablation were 29.7% and 67.6%. The TVRE was significantly associated with the longer interval from diagnosis of severe TR to surgery (hazard ratio: 1.023, 95% confidence interval: 1.005-1.042). Conclusions: TV surgery for TR induced by AF showed low surgical mortality and favorable mid-term outcomes. For these patients, early surgery after progress to severe TR can be helpful to decrease the occurrence of TVRE.

Clinical benefits of surgical ablation during isolated aortic valve replacement: a nationwide study.

OBJECTIVES: To compare the early- and long-term clinical outcomes of concomitant surgical ablation (SA) for atrial fibrillation (AF) during isolated aortic valve replacement (AVR) using data from the Korean National Health Insurance Service Database. METHODS: Of 23,332 adult patients who underwent AVR between 2003 and 2019, those with underlying AF with or without concomitant SA were extracted, and propensity score matching analysis was performed. RESULTS: Overall, 1,741 patients with underlying AF with (n = 445, group A) or without (n = 1,296, group N) concomitant SA during isolated AVR were enrolled, from whom 435 pairs were matched in a 1:1 ratio using propensity score matching analysis. The operative mortality and early postoperative morbidities, including bleeding reoperation, stroke, permanent pacemaker implantation and acute kidney injury were comparable between the groups. The overall survival showed no differences between the groups. However, the cumulative incidence of new-onset late ischaemic stroke was significantly lower in group A than group N in propensity score-matched patients [2.3 vs 3.5 per 100 patient-years, adjusted hazard ratio (95% confidence interval) 0.64 (0.43-0.96), Group A versus Group N, respectively]. The cumulative incidence of other morbidities such as reoperation, permanent pacemaker implantation and progression to chronic renal failure showed no difference between groups. CONCLUSIONS: The incidence of late ischaemic stroke was significantly lower when concomitant SA was performed during isolated AVR in patients with underlying AF. Therefore, concomitant SA should be actively considered in patients with underlying AF undergoing isolated AVR to prevent the occurrence of late ischaemic stroke.

Optimal timing of heart transplantation in patients with an implantable left ventricular assist device.

Heart transplantation (HTPL) has been established as the gold-standard surgical treatment for end-stage heart failure. However, the use of a left ventricular assist device (LVAD) as a bridge to HTPL has been increasing due to the limited availability of HTPL donors. Currently, more than half of HTPL patients have a durable LVAD. Advances in LVAD technology have provided many benefits for patients on the waiting list for HTPL. Despite their advantages, LVADs also have limitations such as loss of pulsatility, thromboembolism, bleeding, and infection. In this narrative review, the benefits and shortcomings of LVADs as a bridge to HTPL are summarized, and the available literature evaluating the optimal timing of HTPL after LVAD implantation is reviewed. Because only a few studies have been published on this issue in the current era of third-generation LVADs, future studies are needed to draw a definite conclusion.

Comparative effectiveness of clopidogrel versus aspirin as a maintenance monotherapy 1 year after coronary artery bypass grafting.

OBJECTIVES: Data on the safety and efficacy of clopidogrel (CPD) monotherapy after coronary artery bypass grafting (CABG) are limited. We compared the clinical outcomes and graft patency rates during 4 years in CABG patients who maintained CPD or aspirin after 1 year of dual antiplatelet therapy (DAPT) use. METHODS: A total of 671 patients who maintained 1-year DAPT after CABG with all grafts patent on one-year follow-up angiography and switched to single antiplatelet therapy (SAPT) using CPD (n = 272) or aspirin (n = 399) between January 2009 and December 2015 were enrolled. Propensity score matching analysis was used, and 227 pairs were matched in a 1:1 ratio. Overall mortality, cardiac mortality, and major adverse events, including all-cause mortality, acute myocardial infarction, coronary reintervention or reoperation, ischaemic stroke, and major bleeding, were compared. Graft patency was evaluated using graft angiography 5 years post-surgery. RESULTS: Overall survival and the incidence of major adverse events during the 4-year follow-up did not differ significantly between the groups when un-matched (hazard ratio [HR], 95% confidence interval [CI]=1.24, 0.71 to 2.15, P = 0.46 and HR, 95% CI = 1.22, 0.77 to 1.92, P = 0.41, respectively) or matched (HR, 95% CI = 1.05, 0.55 to 2.01, P = 0.89 and HR, 95% CI = 1.01, 0.60 to 1.73, P = 0.96, respectively). In the postoperative 5-year graft angiography, new graft occlusion was found in 3.2% and 4.7% of patients and newly occurred graft occlusion rates of distal anastomoses were 1.2% and 1.6% in the CPD and aspirin groups, respectively, and were not statistically different between the 2 groups (P = 0.39 and 0.63, respectively). Changes of antiplatelet regimen were needed in 22.8% (91 of 399) of aspirin group and in 2.2% (6 of 272) of CPD group from the initiation of SAPT (P < 0.001). CONCLUSIONS: In this series of patients undergoing CABG who received DAPT and remained stable for 1 year, SAPT maintenance with CPD or aspirin did not show any significant differences in 4-year outcomes such as all-cause mortality, major adverse events, and newly occurring graft occlusion. However, more patients taking aspirin required changes in antiplatelet regimens to other antiplatelet or anticoagulation therapies.

Impact of Functional vs Anatomic Complete Revascularization in Coronary Artery Bypass Grafting.

BACKGROUND: This study was conducted to evaluate the impact of functional and anatomic complete revascularization on long-term clinical outcomes after coronary artery bypass grafting (CABG). METHODS: Of 2034 patients who underwent primary isolated CABG between 2006 and 2017, 1162 patients who underwent off-pump CABG for 3-vessel disease and for whom data on functional and anatomic completeness of revascularization were available on the basis of preoperative myocardial single photon emission computed tomography and early postoperative graft angiography were enrolled. The median follow-up duration was 82.4 months (interquartile range, 50.8-122.4 months). Univariate and multivariate analyses were performed to evaluate the impact of the functional and anatomic completeness of revascularization on long-term survival. RESULTS: Of 1162 patients, anatomic complete revascularization was achieved in 1014 patients (87.3%), whereas functional complete revascularization was achieved in 1077 patients (92.7%). Early mortality occurred in 7 patients. Late death occurred in 322 of 1155 early survivors. The 5- and 10-year overall survival rates were 84.3% and 66.7%, respectively. Univariate analyses demonstrated that functional completeness of revascularization was a statistically significant risk factor (P = .038), whereas anatomic completeness was not (P = .859). The multivariate analysis showed that functional completeness of revascularization (hazard ratio, 1.54; 95% CI, 1.08-2.22; P = .019) and age, underweight status, diabetes mellitus, chronic kidney disease, chronic obstructive pulmonary disease, and left ventricular dysfunction were significant factors associated with long-term survival. CONCLUSIONS: Functional rather than anatomic completeness of revascularization has a significant impact on the long-term survival in patients who undergo CABG.

Incidence of and Risk Factors for the Development of Significant Tricuspid Regurgitation after Isolated Aortic Valve Replacement.

Background: The late progression of tricuspid regurgitation (TR) after mitral valve surgery is well known. However, few reports have described the progression of TR after aortic valve surgery. We investigated the incidence of and risk factors for the development of significant TR after isolated aortic valve replacement (AVR). Methods: This study analyzed patients with less than moderate TR who underwent isolated AVR at Seoul National University Hospital from January 1990 to December 2018. Significant TR was defined as moderate or higher. Echocardiographic follow-up was performed in all patients. The Fine-Gray model was used to identify clinical risk factors for the development of significant TR. Results: In total, 583 patients (61.7±14.2 years old) were included. Operative mortality occurred in 9 patients (1.5%), and the overall survival rates at 10, 20, and 25 years were 91.1%, 83.2%, and 78.9%, respectively. Sixteen patients (2.7%) developed significant TR during the follow-up period (13 moderate; 3 severe). The cumulative incidence of significant TR at 10, 20, and 25 years was 0.77%, 3.83%, and 6.42%, respectively. No patients underwent reoperation or reintervention of the tricuspid valve. Hemodialysis or peritoneal dialysis for chronic kidney disease (hazard ratio [HR], 5.188; 95% confidence interval [CI], 1.154-23.322) and preoperative mild TR (HR, 5.919; 95% CI, 2.059-17.017) were associated with the development of significant TR in the multivariable analysis. Conclusion: TR progression after isolated AVR in patients with less than moderate TR is rare. Preoperative mild TR and hemodialysis or peritoneal dialysis for chronic kidney disease were significant risk factors for the development of TR.

Machine-learning-based prediction of survival and mitral regurgitation recurrence in patients undergoing mitral valve repair.

OBJECTIVES: This study was conducted to assess long-term clinical outcomes after mitral valve repair using machine-learning techniques. METHODS: We retrospectively evaluated 436 consecutive patients (mean age: 54.7 ± 15.4; 235 males) who underwent mitral valve repair between January 2000 and December 2017. Actuarial survival and freedom from significant (≥ moderate) mitral regurgitation (MR) were clinical end points. To evaluate the independent risk factors, random survival forest (RSF), extreme gradient boost (XGBoost), support vector machine, Cox proportional hazards model and general linear models with elastic net regularization were used. Concordance indices (C-indices) of each model were estimated. RESULTS: The operative mortality was 0.9% (N = 4). Reoperation was required in 15 patients (3.5%). In terms of C-index, the overall performance of the XGBoost (C-index 0.806) and RSF models (C-index 0.814) was better than that of the Cox model (C-index 0.733) in overall survival. For the recurrent MR, the C-index for XGBoost was 0.718, which was the highest among the 5 models. Compared to the Cox model (C-index 0.545), the C-indices of the XGBoost (C-index 0.718) and RSF models (C-index 0.692) were higher. CONCLUSIONS: Machine-learning techniques can be a useful tool for both prediction and interpretation in the survival and recurrent MR. From the machine-learning techniques examined here, the long-term clinical outcomes of mitral valve repair were excellent. The complexity of MV increased the risk of late mitral valve-related reoperation.