Jae Suk Yoo

Coronary artery bypass grafting in patients with left ventricular dysfunction: Predictors of long-term survival and impact of surgical strategies

BACKGROUND In the surgical management of ischemic cardiomyopathy, factors associated with long-term prognosis after coronary artery bypass grafting (CABG) in patients with severe left ventricular (LV) dysfunction are poorly understood. This study aimed to determine predictors of clinical outcomes in patients with severe LV dysfunction undergoing CABG. METHODS Out of 6084 patients who underwent CABG between 1997 and 2011, 476 patients (aged 62.6 ± 9.3 years, 100 females) were identified as having severe LV dysfunction (ejection fraction ≤ 35%), preoperatively. All-cause mortality and adverse cardiac events (myocardial infarction, repeat revascularization, stroke and hospitalization due to cardiovascular causes) were evaluated during a median follow-up period of 55.2 months (inter-quartile range: 26.4-94.8 months). RESULTS During the follow-up, 187 patients (39.3%) died and 126 cardiac events occurred in 104 patients (21.8%). Five-year survival and event-free survival rates were 72.1 ± 2.2% and 61.3 ± 2.4%, respectively. On Cox-regression analysis, old age (P < 0.001), recent MI (P < 0.001), history of coronary stenting (P = 0.023), decreased glomerular filtration rate (P < 0.001), and presence of mitral regurgitation (≥moderate) (P = 0.012) or LV wall thinning (P = 0.007) emerged as significant and independent predictors of death. After adjustment for important covariates affecting outcomes, none of the pump strategy (off-pump vs. on-pump), concomitant mitral surgery or surgical ventricular reconstruction (SVR) affected survival or event-free survival (P = 0.082 to >0.99). CONCLUSIONS Long-term survival following CABG in patients with severe LV dysfunction was affected by age, renal function, recent MI, prior coronary stenting, and presence of mitral regurgitation or LV wall thinning. Neither concomitant mitral surgery nor SVR, however, had significant influence on clinical outcomes.

Surgical repair of descending thoracic and thoracoabdominal aortic aneurysm involving the distal arch: Open proximal anastomosis under deep hypothermia versus arch clamping technique

BACKGROUND Surgical repair of a descending thoracic and thoracoabdominal aortic aneurysm (DTA/TAAA) involving the distal arch is challenging and requires either deep hypothermic circulatory arrest (DHCA) or crossclamping of the distal arch. The aim of this study was to compare these 2 techniques in the treatment of DTA/TAAA involving the distal arch. METHODS From 1994 to 2012, 298 patients underwent open repair of DTA/TAAA through a left thoracotomy. One hundred seventy-four patients with distal arch involvement who were suitable for either DHCA (n=81) or arch clamping (AC; n=93), were analyzed. In-hospital outcomes were compared using propensity scores and inverse-probability-of-treatment weighting adjustment to reduce treatment selection bias. RESULTS Early mortality was 11.1% in the DHCA group and 8.6% in the AC group (P=.58). Major adverse outcomes included stroke in 16 patients (9.2%), low cardiac output syndrome in 15 (8.6%), paraplegia in 10 (5.7%), and multiorgan failure in 10 (5.7%). After adjustment, patients who underwent DHCA were at similar risk of death (odds ratio [OR], 1.14; P=.80) and permanent neurologic injury (OR, 0.95; P=.92) to those who underwent AC. Although prolonged ventilator support (>24 hours) was more frequent with DHCA than with AC (OR, 2.60; P=.003), DHCA showed a tendency to lower the risk of paraplegia (OR, 0.15; P=.057). CONCLUSIONS Compared with AC, DHCA did not increase postoperative mortality and morbidity, except for prolonged ventilator support. However, DHCA may offer superior spinal cord protection to AC during repair of DTA/TAAA involving the distal arch.

Deep hypothermic circulatory arrest versus non-deep hypothermic beating heart strategy in descending thoracic or thoracoabdominal aortic surgery

OBJECTIVES The ideal cardiopulmonary bypass (CPB) strategy during open surgical repair of the descending thoracic aorta (DTA) or thoracoabdominal aorta (TAA) is controversial. This study aimed to compare the clinical outcomes between deep hypothermic circulatory arrest (DHCA) and non-deep hypothermic beating heart CPB (non-DHCA) for DTA or TAA replacement. METHODS From January 1994 to August 2011, 259 patients underwent DTA or TAA replacement. Of these, 212, who were judged to be suitable for both DHCA (n = 79) and non-DHCA (n = 109), were analysed. In-hospital outcomes were compared using propensity scores and inverse-probability-weighting adjustment based on 20 preoperative variables to reduce treatment selection bias. RESULTS Early mortality was 12.7% in the DHCA group and 7.5% in the non-DHCA group (P = 0.23). Major adverse outcomes included stroke in 13 patients (6.1%), paraplegia in 10 (4.7%), low cardiac output syndrome (LCOS) in 17 (8.0%) and multiorgan failure in 12 (5.7%). After adjustment, patients who underwent DHCA were at a risk of death (odds ratio (OR), 1.86; P = 0.18) and permanent neurological injury (OR, 1.06; P = 0.90) similar to that of those who underwent non-DHCA, but at greater risk of LCOS (OR, 3.85; P = 0.012). Furthermore, prolonged ventilator support (>24 h) was more frequent with DHCA than with non-DHCA (OR, 2.33; P = 0.004). CONCLUSIONS Compared with non-DHCA, DHCA was associated with greater risk of postoperative LCOS and prolonged ventilator support. Therefore, non-DHCA seems to be a more appropriate option than DHCA for open DTA/TAA repair whenever the aortic anatomy lends itself to this approach.

Venovenous Extracorporeal Membrane Oxygenation for Postoperative Acute Respiratory Distress Syndrome.

Background Extracorporeal membrane oxygenation (ECMO) has recently attracted interest as a treatment for severe acute respiratory distress syndrome (ARDS). However, the outcomes of this procedure in post-surgical settings have not yet been characterized. In this study, we evaluated the outcomes of ECMO in patients with severe postoperative ARDS. Methods From January 2007 to December 2012, a total of 69 patients (aged 58.3±11.5 years, 23 females) who underwent venovenous ECMO to treat severe postoperative ARDS were reviewed. Of these patients, 22 (31.9%) had undergone cardiothoracic surgery, 32 (46.4%) had undergone liver transplantation, and 15 (21.7%) had undergone other procedures. Results Thirty-four patients (49.3%) were successfully weaned from ECMO, while the other 35 patients (50.7%) died on ECMO support. Among the 34 patients who were successfully weaned from ECMO, 21 patients (30.4%) eventually died before discharge from the hospital, resulting in 13 hospital survivors (18.8%). Multivariable analysis showed that the duration of pre-ECMO ventilation was a significant independent predictor of death (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.29 to 3.90; p=0.004), whereas the concomitant use of continuous venovenous hemodialysis (CVVHD) was associated with improved survival (OR, 0.55; 95% CI, 0.31 to 0.97; p=0.038). Conclusion Although the overall survival rate of patients treated with ECMO for postoperative ARDS was unfavorable, ECMO offered an invaluable opportunity for survival to patients who would not have been expected to survive using conventional therapy. CVVHD may be beneficial in improving the outcomes of such patients, whereas a prolonged duration of pre-ECMO ventilator support was associated with poor survival.

Impact of the maze procedure and postoperative atrial fibrillation on progression of functional tricuspid regurgitation in patients undergoing degenerative mitral repair

OBJECTIVES The aim of this study is to investigate the factors contributing to the progression of functional tricuspid regurgitation (TR) after mitral repair for degenerative mitral regurgitation (MR) in relation to pre and postoperative atrial fibrillation (AF) and performance of the maze procedure. METHODS We assessed 398 patients with less than moderate TR who did not undergo tricuspid valve repair at the time of isolated mitral valve repair for degenerative MR between January 1999 and January 2010. RESULTS Clinical follow-up was complete in 385 patients (96.7%) with a median follow-up of 48.3 months (range 0.13-148.5). During this time, there were 21 late deaths (5.5%) and 17 major complications (4.4%), including 11 reoperations for MR recurrence (2.9%). On late follow-up echocardiography performed on 395 patients (median 44.6 months, range 6.0-147.3), 34 (9.6%) experienced moderate or greater MR and 16 (4.5%) experienced moderate or greater TR. The 5-year freedom from moderate or greater MR and moderate or greater TR rates were 88.3 ± 2.1 and 95.3 ± 1.5%, respectively. Time-updated Cox regression analysis showed that male gender [hazard ratio (HR) 3.83, 95% confidence interval (CI) 1.28-11.40, P = 0.016], New York Heart Association functional class III or IV (HR 2.64, 95% CI 0.88-8.00, P = 0.085), preoperative AF without maze (HR 10.48, 95% CI 2.49-44.21, P = 0.001), and postoperative AF (HR 14.56, 95% CI 4.46-47.58, P < 0.001) were significant risk factors for postoperative moderate or greater TR. Of the 79 patients with preoperative AF, 68 (86.1%) underwent concomitant maze procedures. Of them, eight (11.8%) experienced late AF (>3 months) recurrence. Freedom from AF at 5 years after the concomitant maze procedure was 87.8 ± 4.6%. CONCLUSIONS Preoperative AF without the maze procedure and postoperative AF can contribute to the development of moderate or greater functional TR after mitral repair for degenerative MR.

Minimally Invasive Trans-Mitral Septal Myectomy to Treat Hypertrophic Obstructive Cardiomyopathy.

A 43-year-old man with symptomatic hypertrophic obstructive cardiomyopathy (HOCM) was admitted to our hospital with aggravated exertional dyspnea and successfully treated with robotic transmitral septal myectomy. Minimally invasive transmitral septal myectomy may be a feasible surgical option for the treatment of HOCM in selected cases as an alternative to transaortic myectomy.

Extracorporeal life support for adults with refractory septic shock

Objective Although the use of extracorporeal membrane oxygenation (ECMO) in shock patients is increasing worldwide, studies concerning this treatment for adult septic shock are limited. This study aimed to analyze the outcome of venoarterial ECMO in adult patients with septic shock refractory to conventional treatment. Methods A total of 71 consecutive patients who presented with septic shock and underwent venoarterial ECMO were reviewed. Clinical parameters were compared between survivors and nonsurvivors. Weaning and survival outcomes of these patients were compared with the control group of 253 patients who received venoarterial ECMO for cardiogenic shock. Results The mean age was 56.0 ± 12.3 years. Of the 71 septic shock patients, 11 (15.5%) were successfully weaned from ECMO after a median of 7.9 [interquartile range (IQR), 6.3‐10.2] days, 5 of whom (7.0%) survived to discharge. Pre‐ and 6 hours post‐procedural lactate levels were significantly higher in the nonsurvivors (11.6 [IQR, 7.5‐15.0] vs 5.8 [IQR, 4.3‐5.9], P = .036; 15.0 [IQR, 11.1‐15.0] vs 5.2 [IQR, 4.7‐5.4], P = .002). Rates of successful weaning from venoarterial ECMO (15.5% vs 45.5%), and of survival up to hospital discharge (7.0% vs 28.9%) were significantly lower in septic shock than in cardiogenic shock patients (n = 253; P < .001). Conclusions Outcomes of ECMO in refractory septic shock patients were poor with a very low probability of survival. This finding raises questions concerning the utility of applying ECMO for medically refractory septic shock. Elevated arterial lactate levels pre‐ and post‐ECMO were associated with risk of in‐hospital death. Further large‐scale studies are needed to validate the results of this study.

Minimally Invasive Approach for Redo Mitral Valve Replacement: No Aortic Cross-Clamping and No Cardioplegia

A 75-year-old woman who had previously undergone a double valve replacement was admitted to Asan Medical Center because of severe bioprosthetic mitral valve dysfunction and tricuspid regurgitation. Under hypothermic fibrillatory arrest without aortic cross-clamping, minimally invasive mitral and tricuspid valve surgery was performed via a right minithoracotomy.

Outcomes of Open Surgical Repair of Descending Thoracic Aortic Disease

Background To determine the predictors of clinical outcomes following surgical descending thoracic aortic (DTA) repair. Methods We identified 103 patients (23 females; mean age, 64.1±12.3 years) who underwent DTA replacement from 1999 to 2011 using either deep hypothermic circulatory arrest (44%) or partial cardiopulmonary bypass (CPB, 56%). Results The early mortality rate was 4.9% (n=5). Early major complications occurred in 21 patients (20.3%), which included newly required hemodialysis (9.7%), low cardiac output syndrome (6.8%), pneumonia (7.8%), stroke (6.8%), and multi-organ failure (3.9%). None experienced paraplegia. During a median follow-up of 56.3 months (inter-quartile range, 23.1 to 85.1 months), there were 17 late deaths and one aortic reoperation. Overall survival at 5 and 10 years was 80.9%±4.3% and 71.7%±5.9%, respectively. Reoperation-free survival at 5 and 10 years was 77.3%±4.8% and 70.2%±5.8%. Multivariable analysis revealed that age (hazard ratio [HR], 1.10; 95% confidence interval [CI], 1.05 to 1.15; p<0.001) and left ventricle (LV) function (HR, 0.88; 95% CI, 0.82 to 0.96; p<0.003) were significant and independent predictors of long-term mortality. CPB strategy, however, was not significantly related to mortality (p=0.49). Conclusion Surgical DTA repair was practicable in terms of acceptable perioperative mortality/morbidity as well as favorable long-term survival. Age and LV function were risk factors for long-term mortality, irrespective of the CPB strategy.

Heart Transplantation in a Patient with Left Isomerism

We report the case of a 37-year-old man who suffered from biventricular failure due to left isomerism, inferior vena cava interruption with azygos vein continuation, bilateral superior vena cava, double outlet of right ventricle, complete atrioventricular septal defect, pulmonary stenosis, and isolated dextrocardia. Heart transplantation in patients with systemic venous anomalies often requires the correction and reconstruction of the upper & lower venous drainage. We present a case of heart transplantation in a patient with left isomerism, highlighting technical modifications to the procedure, including the unifocalization of the caval veins and reconstruction with patch augmentation.