Sven Lehmann

Aortic Valve Replacement in Octogenarians: Utility of Risk Stratification With EuroSCORE

BACKGROUND With the advent of percutaneous valve implantation, an increasing amount of interest is being expressed in outcomes of conventional aortic valve replacement (AVR) in elderly patients. We evaluated characteristics and outcomes of elderly patients undergoing isolated AVR with a particular focus on the European System for Cardiac Operative Risk Evaluation (EuroSCORE) risk stratification. METHODS All patients aged 80 years or older (n = 282) undergoing isolated AVR between November 1995 and June 2006 at our institution were reviewed according to logistic EuroSCORE (ES(log)) risk stratification. Surgical risk was defined as low risk (ES(log) < or = 10% [n = 107]), moderate risk (10% < ES(log) < 20% [n = 103]), and high risk (ES(log) > or = 20% [n = 72]). Patient age was 82 +/- 2 years (low risk), 82.7 +/- 2.7 years (moderate risk), and 83.6 +/- 3.1 years (high risk), respectively (p < 0.05). Mean ES(log) predicted risk of mortality was 7.3% +/- 1.4% (low risk), 13.7% +/- 2.5% (moderate risk), and 33.0% +/- 11.5% (high risk; p < 0.05). Follow-up was 99.7% complete. RESULTS In-hospital mortality was 7.5% (low risk), 12.6% (moderate risk), and 12.5% (high risk; p = 0.4). One-year survival was 90%, 78%, and 69% (p = 0.002); 5-year survival was 70%, 53%, and 38% (p = 0.05); and 8-year survival was 38%, 33%, and 21% (p = 0.017), for low-, moderate-, and high-risk patients, respectively. Independent predictors for in-hospital mortality were pulmonary hypertension and urgent indication for surgery. Cox regression predictors of medium-term survival were congestive heart failure, urgent timing, previous stroke or transient ischemic attack, and EuroSCORE stratum. CONCLUSIONS Aortic valve replacement can be performed in the elderly population with acceptable outcomes. EuroSCORE risk stratification is imprecise for prediction of perioperative mortality among octogenarian AVR patients, but may be useful for predicting mortality during medium-term follow-up.

What Is the Best Strategy for Brain Protection in Patients Undergoing Aortic Arch Surgery? A Single Center Experience of 636 Patients

BACKGROUND Cerebral protection during aortic arch surgery can be performed using various surgical strategies. We retrospectively analyzed our results of different brain protection modalities during aortic arch surgery. METHODS Between January 2003 and November 2009, 636 consecutive patients underwent aortic arch replacement surgery using unilateral antegrade cerebral perfusion (UACP [n=123]), bilateral antegrade cerebral perfusion (BACP [n=242]), retrograde cerebral perfusion (RCP [n=51]), or deep hypothermia and circulatory arrest (DHCA [n=220]). Mean age of patients was 62±14 years, 64% were male, 15% were reoperations, and 37% were performed for acute type A dissections. Mean follow-up was 4.9±0.1 years and was 97% complete. RESULTS Circulatory arrest time was 22±17 minutes UACP, 23±21 minutes BACP, 18±12 minutes RCP, and 15±13 minutes DHCA; p<0.001). Early mortality was 11% (n=72) and was not different between the surgical groups. Stroke rate was 9% for ACP patients (n=33) versus 15% (n=39) for patients who did not receive ACP (p=0.035). Independent predictors of stroke were type A aortic dissection (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.3 to 3.2; p<0.001), age (OR, 1.04; 95% CI, 1.01 to 1.06; p=0.001), duration of circulatory arrest (OR, 1.01, 95% CI, 1.002 to 1.03; p=0.02), and total aortic arch replacement (OR, 2.7; 95% CI, 1.3 to 5.7; p=0.005). Five year survival was 68%±4% and was not significantly different between groups. CONCLUSIONS Antegrade cerebral perfusion is associated with significantly less neurologic complications than RCP and DHCA, despite longer circulatory arrest times. Medium-term survival is worse for patients with postoperative permanent neurologic deficit and preoperative type A aortic dissection.

Does Reasonable Incomplete Surgical Revascularization Affect Early or Long-Term Survival in Patients With Multivessel Coronary Artery Disease Receiving Left Internal Mammary Artery Bypass to Left Anterior Descending Artery?

Background— The objective was to evaluate the impact of complete revascularization (CR) versus reasonable incomplete surgical revascularization (IR) in others than left anterior descending artery territory on early and late survival in patients with multivessel coronary artery disease (CAD). Methods and Results— During a 7-year period, 8.806 consecutive patients with multivessel CAD affecting the proximal left anterior descending artery or left main stem underwent sternotomy for isolated coronary artery bypass grafting including left internal mammary artery–left anterior descending artery bypass. A total of 936 patients (10.6%) had IR of the circumflex or right coronary artery territory. IR was based on the traditional classification. Follow-up was 3.5±2.2 years. Patient groups were comparable regarding age (CR 67.1 versus IR 67.6 years), ejection fraction (57.2% versus 57.5%), and logEuroscore (4.5% versus 4.5%). Patients receiving IR presented with more complex CAD. Mean number of distal anastomoses was 3.0±0.8 CR versus 2.4±0.6 IR. Operation time (176 versus 187 minutes) and cross-clamp time (52 versus 56 minutes) were longer in the IR group (P<0.001). Hospital mortality was 3.3% CR versus 3.2% IR (P=0.520). Independent risk factors for hospital mortality were age, pulmonary hypertension, chronic obstructive pulmonary disease, peripheral vascular disease, and emergency indication, but not IR (P=0.922). Arterial revascularization was protective. Cumulative survival at 1-year was 93.1% CR versus 93.6% IR and at 5 years 82.2 CR versus 80.9% IR (P=0.457). Conclusions— In presence of left internal mammary artery-to-left anterior descending artery bypass, reasonable IR of the circumflex or right coronary artery territory did not adversely affect early or long-term survival in patients with multivessel CAD. In patients presenting with 1 poor target vessel; however, IR is a good therapeutic option and the benefit of CR should be balanced against the risks.

Autopsy findings in patients on postcardiotomy extracorporeal membrane oxygenation (ECMO).

Objectives To assess the clinical sensitivity of causes of death, concomitant diseases and postoperative complications including thromboembolic events in ECMO patients. Methods: Between January 2000 and December 2004 154/202 patients (76.2%) died after postcardiotomy ECMO circulatory support. Autopsy was performed in 78 (50.6%) consecutive patients. Clinical and post-mortem data were prospectively recorded and compared concerning causes of death and postoperative complications including venous and arterial thromboembolisms and significant comorbidities. Results Mean age was 62.1±11.3 years, ejection fraction was 43.4±17.3%. 39.7% were emergency operations including acute coronary syndrome in 25.6% and preoperative cardiogenic shock in 28.2%. Successful ECMO weaning rate was 43.6%. Mean postoperative survival was 11.3 days. Premortem unknown concomitant diseases were found in 63 patients (80.8%) with clinical relevance in 9 patients (11.5%). Clinically unrecognized postoperative complications were found in 59 patients (75.6%) including acute cerebral infarction (n=7), acute bowel ischemia (1), intestinal perforation (3), pneumonia (4), venous thrombus formation (25) and systemic thromboembolic events (24). Clinically based causes of death were cardiac in 62.8%, multi-organ failure in 10.3%, cerebral in 5.1%, respiratory in 10.3%, fatal pulmonary embolism in 2.6%, technical in 5.1%, and others in 3.8%. Unexpected causes of death were found by autopsy in 22 patients (28.2%) including myocardial infarction (n=5), acute heart failure (4), fatal pulmonary embolism (2), pneumonia (2), ARDS (1), lung bleeding (1), fatal cerebrovascular event (4) and multiorgan failure (3). Conclusions In ECMO patients major discrepancies between clinical and post-mortem examination were found. The true incidence of thromboembolic events is highly underestimated by clinical evaluation.

Redo Aortic Valve Surgery: Early and Late Outcomes

BACKGROUND Repeat aortic valve surgery (rAVS) is usually associated with an increased risk profile due to advanced patient age and comorbidities. We analyzed the current early and late results for isolated rAVS. METHODS One hundred fifty-five patients underwent isolated rAVS from November 1994 to April 2008, of which, 86 received isolated redo aortic valve surgery (rAVS without root) and 69 received aortic root replacement (rAVS with root) as the second operation. RESULTS Patient age was 58 ± 16 years; 23% were female. The indications for redo surgery were infective endocarditis (27.1%, n = 42), bioprosthetic structural valve dysfunction and degeneration (23.8%, n = 37), mechanical valve nonstructural dysfunction (7.2%, n = 11), paravalvular leak (18.1%, n = 28), aortic dissection (2.6%, n = 4), and aortic aneurysm (7.1%, n = 11). Early mortality was 4.5% (n = 7) for all patients (3.5% for rAVS without root and 5.8% for rAVS with root, p = 0.5). Left ventricular ejection fraction less than 0.30 (odds ratio 9.2, 95% confidence interval [CI] 1.1 to 80.3) and preoperative neurologic dysfunction (odds ratio 22.1, 95% CI 2.3 to 197.4) were found to be the independent predictors for in-hospital mortality according to multivariate analysis. Follow-up was 100% complete with a mean duration of 2.7 ± 2.8 years for all patients. Five-year and eight-year survival was 66% ± 5% and 61% ± 6% for all patients and did not significantly differ between surgical groups. Cox regression analysis revealed the following independent predictors of long-term survival: preoperative New York Heart Association functional class IV (hazard ratio 2.2, 95% CI 1.5 to 3.2, p < 0.01) and infective endocarditis (hazard ratio 2.2, 95% CI 1.4 to 3.1, p < 0.01). CONCLUSIONS Repeat isolated aortic valve surgery is associated with respectable outcomes. Follow-up results reveal good long-term survival for this group.

Minimal invasive aortic valve replacement surgery is associated with improved survival: a propensity-matched comparison

OBJECTIVES To compare early and long-term outcomes of minimally invasive surgery (MIS) versus full sternotomy (FS) isolated aortic valve replacement (AVR). METHODS We retrospectively analysed all patients who underwent isolated bioprosthetic AVR between 2003 and March 2012 at our institution. Matching was performed based on a propensity score, which was obtained using the output of a logistic regression on relevant preoperative risk factors. Mean follow-up was 3.1±2.7 years (range 0-9.0 years) and was 99.8% complete. RESULTS A total of 2051 patients (FS, 1572; MIS, 479) underwent isolated bioprosthetic AVR during the study period. MIS patients were significantly younger (67.8±11.2 vs 70.4±9.4 years) and had a lower logistic EuroSCORE (6.6±6.4 vs 11.2±13.4%, both P<0.001). Propensity matching resulted in 477 matched patients from each group, with no significant differences in any of the preoperative variables. Aortic cross-clamp times were significantly longer in MIS patients (59.4±16.0 vs 56.9±14.6 min, P=0.008). Nonetheless, MIS AVR was associated with a significantly lower incidence of intra-aortic balloon pump usage (0.4 vs 2.1%, P=0.042) and in-hospital mortality (0.4 vs 2.3%, P=0.013), while FS patients had a lower rate of re-exploration for bleeding (1.5 vs 4.2%, P=0.019). Five- and 8-year survival post-AVR was significantly higher in MIS patients (89.3±2.4% and 77.7±4.7% vs 81.8±2.2% and 72.8±3.1%, respectively, P=0.034). Cox regression analysis revealed MIS (hazard ratio: 0.47, 95% confidence interval: 0.26-0.87) as an independent predictor of long-term survival. CONCLUSION MIS AVR is associated with very good early and long-term survival, despite longer myocardial ischaemic times. MIS AVR can be performed safely with results that are at least equivalent to those achieved through an FS.

Minimally invasive off-pump valve-in-a-valve implantation: the atrial transcatheter approach for re-operative mitral valve replacement

AIMS This study was designed to evaluate the feasibility and haemodynamic performance of transcatheter valve-in-a-valve (VinV) implantation for failed mitral xenografts using a minimally invasive, transatrial, off-pump approach. METHODS AND RESULTS Nine adult sheep (71.1 +/- 3.4 kg) underwent mitral valve replacement with a 25 mm bioprosthesis using standard conventional techniques. After weaning from cardiopulmonary bypass, a transcatheter 23 mm pericardial prosthesis mounted on a balloon-inflatable steel stent was deployed within the conventional xenograft. The VinV implantation (10.1 +/- 0.9 min) was performed off-pump using an antegrade transatrial approach under fluoroscopic guidance successfully in all nine sheep. Mean transvalvular gradient was 4.6 +/- 1.0 mmHg, and five of nine sheep had no paravalvular leak with two sheep each having mild and moderate one. All transcatheter prostheses were confirmed in good position on post-mortem analysis. In an in vitro model, the minimum force required to dislodge the valve was 22.5 +/- 3.0 N, which was well above the normal estimated forces generated by the left ventricle (LV). When this model was attached to a LV assist device, the VinV withstood pressure loops of 300 mmHg, without dislocation or embolization. CONCLUSION Transatrial, transcatheter mitral VinV implantation is feasible off pump. This is a truly minimally invasive concept to treat patients with failed xenografts using a right lateral minithoracotomy.

Sternal Closure With Rigid Plate Fixation Versus Wire Closure: A Randomized Controlled Multicenter Trial

BACKGROUND Rigid bone fixation is the standard of care for all bone reconstructions except that after sternotomy. Sternal reconstruction after median sternotomy using rigid fixation with plates may improve bone healing and reduce pain when compared with wire cerclage. METHODS One-hundred forty patients at six centers who were determined preoperatively to be at high risk for sternal wound complications were randomly assigned to sternal closure with rigid plate fixation (n=70) or wire cerclage (n=70). Sternal healing was evaluated at 3 or 6 months by a core laboratory using computed tomography. Pain and function were evaluated at postoperative day 3 through discharge, 3 weeks, 6 weeks, 3 months, and 6 months. RESULTS Sternal healing was superior in rigid plate fixation patients at both 3 and 6 months. Mean computed tomography scores in the rigid plate fixation and wire cerclage groups at 3 months were 1.7±1.1 and 0.9±0.8 (p=0.003). At 6 months, the scores were 3.2±1.6 and 2.2±1.1, respectively (p=0.01). At 6 months, 70% of rigid plate fixation patients had achieved sternal union, compared with 24% of conventional wire cerclage patients (p=0.003). Pain scores and narcotic usage were lower in rigid plate fixation patients. Significant differences in pain scores were observed at 3 weeks for total pain (p=0.020) and pain with coughing (p=0.0084) or sneezing (p=0.030). Complication rates were similar in both groups. CONCLUSIONS Sternal reconstruction using rigid fixation with plates improved bone healing and reduced early postoperative pain compared with wire cerclage.

Outcome of Extracorporeal Membrane Oxygenation as a Bridge to Lung Transplantation and Graft Recovery

BACKGROUND Indications for extracorporeal membrane oxygenation (ECMO) use in lung transplantation are (1) temporary assistance as a bridge to transplantation, (2) stabilization of hemodynamics during transplantation in place of cardiopulmonary bypass, and (3) treatment of severe lung dysfunction and primary graft failure after transplantation. This study compares the survival of lung transplant recipients requiring ECMO support with survival of patients without ECMO. METHODS A retrospective database review was performed for 108 consecutive patients who underwent single-lung or bilateral-lung transplantation at our center between 2002 and 2009. RESULTS Of 108 transplant recipients, 27 (25%) required venoarterial ECMO compared with 81 patients who did not. Nine patients required ECMO preoperatively (87±102 hours), and ECMO was continued for 5 patients during the lung transplant operation. Seven additional patients received ECMO during transplantation. Six patients required early (<7 days) and 5 patients delayed (≥7 days) postoperative ECMO for treatment of allograft dysfunction. The subgroup with support showed the most favorable patient discharge rate (66.7%). ECMO support was a significant risk factor for death (p<0.001). Survival was significantly reduced with the use of ECMO: 30-day, 90-day, 1-year, and 5-year survival was 97%, 91%, 83%, and 58% in the patients without ECMO compared with 63%, 44%, 33%, and 21% in those with ECMO, respectively. CONCLUSIONS Survival after lung transplantation was significantly reduced with ECMO. However, patients who survived the first year showed similar long-term survival as those patients who did not need perioperative ECMO support.

Transapical Aortic Valve Implantation: Therapy of Choice for Patients With Aortic Stenosis and Porcelain Aorta?

BACKGROUND Conventional aortic valve replacement can be technically challenging in patients with porcelain aorta and is associated with a high rate of stroke and mortality. Porcelain aorta is even sometimes seen as contraindication for surgery. Minimally invasive off-pump transapical aortic valve implantation may be an optimal strategy to treat elderly patients with porcelain aorta requiring aortic valve replacement. METHODS Twenty-nine patients with severe aortic stenosis and porcelain aorta underwent transapical aortic valve implantation. Mean age was 79 ± 7.8 years (range, 64 to 93 years), with 65.5% female. Logistic EuroSCORE and the Society of Thoracic Surgeons score were 37.7% ± 18.1% and 12.8% ± 2.2%, respectively. Peripheral vascular disease (41.4%) and carotid artery stenosis (58.6%) were frequent, and 17.2% of patients had experienced a stroke previously. The majority of patients were redo cases (51.2%), and 10.3% were dependent on chronic hemodialysis. In 13.8% of all patients, intraoperatively detected porcelain aorta caused an attempt at conventional aortic valve replacement by means of sternotomy to be aborted. RESULTS All valves were implanted successfully without embolization or aortic dissection. All procedures were primarily performed off-pump, but 4 patients required secondary cardiopulmonary bypass as a result of complications. Median procedure time was 80 minutes, and median intensive care unit stay was 1 day. Stroke occurred in 1 patient only. Thirty-day mortality was 17.2%. Mild paravalvular leak was seen in 31.0%, and mild to moderate regurgitation occurred in 1 patient. CONCLUSIONS Transapical aortic valve implantation is a promising approach to treat elderly patients with porcelain aorta requiring aortic valve replacement. It is associated with acceptable outcome and low stroke rates.