Min Ho Ju

Mitral valve replacement with or without a concomitant Maze procedure in patients with atrial fibrillation

Background Although the Maze procedure is regarded as the most effective way to restore sinus rhythm in patients with chronic atrial fibrillation (AF), it remains unclear whether this procedure offers long-term clinical benefits in patients undergoing mechanical valve replacement. Methods and results Between 1999 and 2007, 402 patients with AF-associated mitral valve (MV) disease underwent MV replacement with a mechanical prosthesis. Of these patients, 159 underwent valve replacement plus the Maze procedure, whereas 243 received valve replacement alone. The composite end points of cardiac death and cardiac-related morbidities were compared in these two groups using the inverse-probability-of-treatment-weighted method. At a median follow-up time of 63.1 months (range 0.2–123.9 months), patients who had undergone the Maze procedure were at significantly lower risk of thromboembolic events (hazard ratio (HR)=0.26, 95% confidence interval (CI) 0.07 to 0.95; p=0.041) and were at comparable risk of death (HR=0.96, 95% CI 0.44 to 2.07; p=0.907) and cardiac death (HR=1.26, 95% CI 0.53 to 3.01; p=0.598) compared with patients who underwent MV replacement alone. The composite risk of death or major events was lower in the Maze procedure group (HR=0.64, 95% CI 0.38 to 1.08; p=0.093). Conclusions Compared with MV replacement alone, the addition of the Maze procedure was associated with a reduction in thromboembolic complications and better long-term event-free survival in patients with AF undergoing mechanical MV replacement. Prospective randomised data are necessary to confirm the findings of this study.

Extracorporeal membrane oxygenation support in a patient with status asthmaticus.

Status asthmaticus is a rare, fatal condition, especially in children. Sometimes respiratory support is insufficient with a mechanical ventilator or medical therapy for patients with status asthmaticus. In such situations, early extracorporeal membrane oxygenation application is a useful method for treating refractory respiratory failure. We report on a case of a six-year-old, male child who underwent venovenous extracorporeal membrane oxygenation support for refractory status asthmaticus.

Surgical Outcomes in Small Cell Lung Cancer

Background The experience of a single-institution regarding surgery for small cell lung cancer (SCLC) was reviewed to evaluate the surgical outcomes and prognoses. Materials and Methods From July 1990 to December 2009, thirty-four patients (28 male) underwent major pulmonary resection and lymph node dissection for SCLC. Lobectomy was performed in 24 patients, pneumonectomy in eight, bilobectomy in one, and segmentectomy in one. Surgical complications, mortality, the disease-free survival (DFS) rate, and the overall survival rate were analyzed retrospectively. Results The median follow-up period was 26 months (range, 4 to 241 months), and there was one surgical mortality (2.9%). Six patients (17.6%) experienced recurrence, all of which were systemic. Eight patients died during follow-up; four died of disease progression and the other four died of pneumonia or of another non-cancerous cause. The three-year DFS rate was 79.2±2.6% and the overall survival rate was 66.4±10.5%. Recurrence or death was significantly prevalent in the patients with lymph node metastasis (p=0.001) as well as in those who did not undergo adjuvant chemotherapy (p=0.008). The three-year survival rate was significantly greater in the patients with pathologic stage I/II cancer than in those with stage III cancer (84% vs. 13%, p=0.001). Conclusion Major pulmonary resection for small cell lung cancer is feasible in selected patients. Patients with pathologic stage I or II disease showed an excellent survival rate after surgery and adjuvant treatment. Prospective randomized studies will be needed to define the role of surgery in early-stage small cell lung cancer.

Valve replacement surgery in severe chronic kidney disease

BACKGROUND The impact of prosthetic choices in patients with severe chronic kidney disease (CKD) on long-term outcomes has not been well established. METHODS The study involved 152 adult patients (61.6±14.1yrs.; 64 females) undergoing heart valve surgery who had stage 4 (n=87) or 5 CKD (end-stage; n=65) based on Kidney Disease Outcomes Quality Initiative Guidelines. To reduce the impact of selection bias between mechanical (n=92) and bio-prostheses groups (n=60), propensity score analyses were conducted. RESULTS Patients undergoing bioprosthetic replacement were significantly older and had poorer left ventricular function compared with those undergoing mechanical valve replacements. Early mortality rates were 10.0% in the Bio-prostheses group and 9.8% in the Mechanical group (P>0.99). During a median duration of 22.1months (Quartile 1-3, 4.7-68.1months; 87.5% complete), 56 patients died and 12 patients experienced valve-related complications. The unadjusted outcomes showed no significant differences in survival (P=0.23) and freedom from valve-related events (P=0.17). After adjustment, there was no significant difference in survival (Hazard ratio [HR], 1.03; 95% confidence interval [CI], 0.62-1.71; P=0.91), however the bio-prostheses group showed significant superior outcomes of freedom from valve-related event (HR, 4.49; 95% CI, 1.04-19.45; P=0.045). CONCLUSIONS Valve replacement in CKD patients showed very high mortality risks and limited life expectancy even in younger individuals. When compared with bioprosthetic replacement, mechanical valve replacement showed similar survival rate but with greater risks of developing major valve-related complications in these patients. Therefore, bioprosthetic replacement may be a more reasonable option over mechanical replacement in these high-risk patients.

Myocardial Injury Following Aortic Valve Replacement for Severe Aortic Stenosis: Risk Factor of Postoperative Myocardial Injury and Its Impact on Long-Term Outcomes

Background As hypertrophied myocardium predisposes the patient to decreased tolerance to ischemia and increased reperfusion injury, myocardial protection is of utmost importance in patients undergoing aortic valve replacement (AVR) for severe aortic valve stenosis (AS). Methods Consecutive 314 patients (mean age, 62.5±10.8 years; 143 females) with severe AS undergoing isolated AVR were included. Postoperative myocardial injury (PMI) was defined as 1) maximum postoperative creatinine kinase isoenzyme MB or troponin-I levels ≥10 times of reference, 2) postoperative low cardiac output syndrome or episodes of ventricular arrhythmia, or 3) left ventricular ejection fraction of less than 55% and decrease in left ventricle (LV) ejection fraction of more than 20% of the baseline value. Results There were 90 patients (28.7%) who developed PMI. There were five cases of early death (1.6%), all of whom had PMI. On multivariable analysis, the use of histidine-tryptophan-ketoglutarate (HTK) solution instead of blood cardioplegia (odds ratio [OR], 3.06; 95% confidence interval [CI], 1.63 to 5.77; p=0.001), greater LV mass (OR, 1.04; 95% CI, 1.01 to 1.07; p=0.007), and increased cardiac ischemic time (OR, 1.13; 95% CI, 1.05 to 1.22; p<0.001) were independent predictors for PMI. Patients who had PMI showed significantly inferior long-term survival than those without PMI (p=0.049). Conclusion PMI occurred in a considerable proportion of patients undergoing AVR for severe AS and was associated with poor long-term survival. HTK cardioplegia, higher LV mass, and longer cardiac ischemic duration were suggested as predictors of myocardial injury.

Comparative effectiveness of coronary screening in heart valve surgery: Computed tomography versus conventional coronary angiography

Background: Although conventional coronary angiography (CAG) is considered the gold standard for coronary artery disease (CAD) screening in the setting of heart valve surgery, coronary artery computed tomography angiography (CCTA) has emerged as an alternative modality. This study was conducted to evaluate the clinical outcomes of CCTA compared with conventional CAG for CAD screening in patients undergoing heart valve surgery. Methods: A total of 3150 consecutive patients aged >40 years or with coronary risk factors undergoing elective valve operations between 2001 and 2015 were evaluated. Of these, 1402 patients underwent CCTA (CT group) and 1748 patients underwent conventional CAG (CAG group) for CAD screening. Results: The 30‐day mortality rates were similar in the 2 groups (2.1% in the CT group vs 1.7% in the CAG group; P = .463); however, the incidence of low cardiac output syndrome was higher in the CT group (2.3% vs 1.0%; P = .008). The final rate of detection of significant CAD (≥50% stenosis) (4.9% vs 9.7%; P < .001) and proportion of receiving coronary bypass grafting (CABG) (2.9% vs 4.3%; P = .041) were lower in the CT group. After adjustment by propensity score matching (563 pairs), the main findings of our crude analyses did not change, with lower rates of CAD detection (odds ratio [OR], 0.56; 95% confidence interval [CI], 0.36‐0.85) and CABG (OR, 0.47; 95% CI, 0.26‐0.81), a similar risk of early mortality (OR, 1.51; 95% CI, 0.54‐4.52), but a higher risk of low cardiac output syndrome (OR, 3.30; 95% CI, 1.16‐11.78) in the CT group compared with the CAG group. Conclusions: The detection of significant CAD and identification of candidates for CABG were inferior with CCTA compared with conventional CAG in patients scheduled for elective heart valve operations.

Thoracic endovascular repair for complicated type B acute aortic dissection with distal malperfusion.

Successful thoracic endovascular repair for complicated Stanford type B acute aortic dissection in two patients is herein reported. The true lumen flow was immediately restored following stent graft deployment in the descending thoracic aorta with subsequent resolution of the distal malperfusion syndrome. One patient is doing well more than 15 months after surgery and another patient who was treated more recently is also doing well 7 months postoperatively.

Refractory Coronary Artery Spasm after Minimally Invasive Direct Coronary Artery Bypass Grafting

Postoperative coronary arterial spasm is a rare but potentially fatal complication. A 51-year-old male patient with a history of a reactive ergonovine stress test coronary angiogram developed refractory coronary artery spasm after undergoing minimally invasive direct coronary artery bypass grafting of the left anterior descending coronary artery. The patient was successfully managed with rapid implementation of intra-aortic balloon-pump counter pulsation and extracorporeal membrane oxygenation.

The Treatment of Left Atrial Appendage Aneurysm by a Minimally Invasive Approach

Left atrial appendage (LAA) aneurysm is a rare, pathologic condition that may lead to atrial tachyarrhythmia or thromboembolic events. A 49-year-old man presented with aggravated palpitation and dizziness. He suffered from refractory atrial fibrillation despite a previous history of radiofrequency catheter ablation. Echocardiography revealed a 57-mm LAA aneurysm. Surgical ablation was performed through a right mini-thoracotomy, and the LAA aneurysm was obliterated with a 50-mm AtriClip (Atricure Inc., Westchester, OH, USA). However, follow-up computed tomography showed residual communication, so the patient is still taking warfarin. We report that a minimally invasive strategy for treating LAA aneurysm can be considered, but incomplete closure may occur; thus, caution is needed.

On-pump beating heart versus conventional coronary artery bypass grafting: comparative study on early and long-term clinical outcomes

Background We reviewed our experience with on-pump beating (OPB) heart coronary artery bypass grafting (CABG) to evaluate the impacts of obviating aortic cross-clamping and cardioplegic arrest on clinical outcomes compared with conventional CABG (C-CABG). Methods Between 2006 and 2012, elective isolated cardiopulmonary bypass (CPB)-assisted CABG was consecutively performed in 645 patients (mean patient age 63.3±9.1 years, 471 women) with 254 (39.4%) undergoing OPB-CABG and 391 (60.6%) undergoing C-CABG. The early and long-term clinical outcomes were compared between the two groups after adjusting for risk profiles through propensity score (PS) analyses. Results The OPB-CABG group presented significant morbidities more frequently than the C-CABG group, including severe chronic kidney disease (CKD) (P=0.026), severe chest pain (P<0.001), and poor left ventricular function (P<0.001). Early mortality occurred in 6 (2.4%) and 2 (0.5%) patients in the OPB- and C-CABG group, respectively (P=0.087). The number of distal anastomosis was comparable between the two groups (3.0±0.9 vs. 3.0±1.0, P=0.816). After PS matching, the incidence of major complications such as stroke (P>0.99) and new-onset dialysis (P=0.109) was comparable. During a median follow-up of 81.0 months (quartiles 1-3, 66.6-95.0 months), 118 patients died and the PS-matched models showed no significant between-group differences in the risk of overall death [hazard ratio (HR), 1.19; 95% confidence interval (CI), 0.72-1.95; P=0.507] and major adverse cardiac events (MACE) (HR, 1.49; 95% CI, 0.67-3.31; P=0.328). Conclusions The OPB strategy may be as safe and effective as the conventional strategy during CABG among patients with similar risk profiles. A prospective randomized trial is warranted to better ascertain the beneficial impact of OPB-CABG as both a viable and a durable alternative strategy to C-CABG.