Alexander Mladenow

Transapical Aortic Valve Implantation: Incidence and Predictors of Paravalvular Leakage and Transvalvular Regurgitation in a Series of 358 Patients

OBJECTIVES The aim of this study was to evaluate the results when the surgical concept of not accepting intraprocedural paravalvular leakage was applied for transcatheter aortic valve implantation (TAVI). BACKGROUND The surgical strategy of conventional aortic valve replacement does not accept paraprosthetic leakage and requires immediate action to eliminate it. However, paravalvular leakage is the major concern after TAVI. METHODS A total of 358 patients underwent transapical TAVI with balloon-expandable prostheses. The modified procedural strategy consisted of precise positioning of the prosthesis using a modified TAVI technique and immediate additional intraprocedural treatment to eliminate relevant paravalvular leakage. RESULTS Balloon redilation of the transcatheter valve was performed in 18 patients (5%), and additional second valves were implanted in 13 (4%). At the end of the procedure, 186 patients (52%) had no paravalvular or transvalvular regurgitation. In the remaining 172 patients, paravalvular leakage was observed in 113 (32%), transvalvular leakage in 47 (13%), and both in 12 (3%). Leakage was trace in 88 patients (25%), mild in 82 (23%), and moderate in 2 (0.6%). Multivariate analysis identified male sex, New York Heart Association functional class IV, and no previous aortic valve replacement as predictors of post-procedural leakage. Cumulative survival was not dependent on post-procedural regurgitation rate. Overall mortality was 5 ± 1% at 30 days, 14 ± 2% at 6 months, 17 ± 2% at 1 year, and 33 ± 4% at 2 years. CONCLUSIONS The modified procedural strategy of transapical TAVI with a balloon-expandable prosthesis was associated with a low incidence of relevant prosthetic regurgitation.

Right-to-left ventricular end-diastolic diameter ratio and prediction of right ventricular failure with continuous-flow left ventricular assist devices.

BACKGROUND Left ventricular assist device (LVAD) implantation is an accepted therapy for patients with end-stage heart failure. Post-operative right ventricular failure (RVF) still remains a major cause of morbidity and mortality in these patients. This study sought to identify echocardiography parameters to select patients with high risk of RVF after LVAD implantation. METHODS Prospectively collected pre-operative transesophageal echocardiography (TEE) and clinical data were evaluated in patients pre-selected for isolated LVAD or biventricular assist device (BiVAD) implantation. According to prevalence of RVF during the first post-operative 48 hours, patients were divided into those who developed RVF (isolated LVAD with RVF) and those who did not (isolated LVAD without RVF). Echocardiographic parameters for RV geometry, RV function, LV geometry, and the RV-to-LV end-diastolic diameter ratio (R/L ratio) were evaluated. For identification of the optimal cutoff of R/L ratio, receiver operating characteristics curves were constructed. RESULTS An isolated LVAD was implanted in 115 patients and BiVAD in 22 patients. RVF developed in 15 patients (13%) after isolated LVAD implantation. The R/L ratio was markedly increased in the isolated LVAD with RVF and BiVAD groups compared with the isolated LVAD without RVF group. According to the receiving operating curve, the cutoff for the R/L ratio to predict RVF was 0.72. The odds ratio that RVF will develop is 11.4 in patients with an R/L ratio >0.72 (p = 0.0001). CONCLUSIONS Increased R/L ratio successfully identifies patients with high risk of RVF after isolated LVAD implantation. Beyond standard measurements of RV function, the consideration of R/L ratio may be useful to improve risk stratification in patients before isolated LVAD implantation.

Transapical aortic valve implantation in 175 consecutive patients: excellent outcome in very high-risk patients.

OBJECTIVES The aim of this study was to evaluate the outcome of transapical aortic valve implantation in a single center with expanded procedural experience and to compare it with predicted risk for conventional aortic valve surgery. BACKGROUND Transapical aortic valve implantation is a new approach for high-risk patients with severe aortic stenosis. There are only limited single-center experiences with very small numbers of patients. METHODS Since April 2008, transapical aortic valve implantation was performed in 175 consecutive patients. The mean patient age was 79.8 +/- 9 years, with a range of 36 to 97 years. The mean Society of Thoracic Surgeons score was 23.5 +/- 19.4% (range 2.7% to 89.5%); 98.3% of patients were in New York Heart Association functional class III or IV. Ten patients were in cardiogenic shock. RESULTS Technical success of the procedure was 100%. There was no conversion to conventional surgery. Cardiopulmonary bypass was used in 8 patients (6 elective, 2 emergency). The 30-day mortality was 5.1% for the entire group, 3.6% for all patients without cardiogenic shock, and 30% for the patients with cardiogenic shock. Survival at 1, 6, and 12 months was 94.9%, 85.5%, and 82.6%, respectively. CONCLUSIONS The outcome of transapical aortic valve implantation was very favorable and already reproducible during the learning curve. The method has become de facto our institutional primary choice for treatment of high-risk patients with severe aortic valve stenosis.

Transcranial Doppler sound detection of cerebral microembolism during transapical aortic valve implantation.

OBJECTIVE Transapical aortic valve implantation (TAVI) is a new method that might reduce the surgical risk of conventional surgical aortic valve replacement in very high-risk patients. Increased downstream microembolization is expected in transapical aortic valve implantation. However, whether it usually occurs, how often, and its clinical relevance are not known. We report the results of ultrasound microembolic signal detection in the middle cerebral artery during the procedure. METHODS Fifty patients (mean age: 80 ± 5 years; mean EuroSCORE: 36 ± 13 %) underwent transapical aortic valve implantation. Intraoperative transcranial Doppler (TCD) sound examination of both middle cerebral arteries (MCA) was used to identify high-intensity transient signals (HITS) and microembolic signals (MES) during seven phases of the procedure. Pre- and postoperative computed tomography of the brain and clinical neurological examinations were performed preoperatively and daily during the first postoperative week. RESULTS During the procedure, HITS [right MCA: 435 ± 922 (range 9-5765); left MCA: 471 ± 996 (range 24-6432)] and MES [right MCA: 78 ± 172 (range 1-955); left MCA: 62 ± 190 (range 2-1553)] were detected in all patients. Most of the MES were recorded during valvuloplasty [right MCA: 3 ± 5.6 (range 0-31); left MCA: 2 ± 4.9 (range 0-30)] and positioning of the prosthetic valve in the aortic position [right MCA: 6 ± 5 (range 0-22); left MCA: 2 ± 6.9 (range 0-38)]. Postoperatively, there were no clinical signs of new cerebral embolism. CONCLUSIONS Cerebral microemboli were detected by intraoperative transcranial Doppler sound examinations in all patients during transapical aortic valve implantation. Most of the signals were detected during balloon valvuloplasty and delivery of the prosthetic valve.

Acute impact of left ventricular unloading by left ventricular assist device on the right ventricle geometry and function: Effect of nitric oxide inhalation

OBJECTIVE Left ventricular assist device (LVAD) implantation is an established option for treatment of patients with end-stage heart failure, but outcome may be worsened by right ventricular failure. The aim of this study was to evaluate the acute effect of LVAD on right ventricular geometry and function and the pulmonary circulation. The effect of inhaled nitric oxide (iNO) was assessed. METHODS We evaluated pre- and postoperatively obtained transesophageal echocardiography images and hemodynamics of patients participating in a randomized trial on the effect of inhaled nitric oxide during LVAD implantation. Twenty-four patients were randomized to the iNO group and 23 to the placebo group. RESULTS After LVAD implantation marked decreases in pulmonary capillary wedge pressure (P < .01) and mean pulmonary artery pressure (P < .01) were observed in both groups. Pulmonary vascular resistance decreased only in the iNO group (311 ± 35 to 225 ± 17, P < .01). Transesophageal echocardiography measurements show significant improvement of right ventricular geometry (right ventricular end-diastolic diameter: 50 ± 2 to 45 ± 2, P < .01 and 48 ± 2 to 44 ± 2 mm, P < .05 in iNO and placebo groups) and function (right ventricular fractional area change: 24% ± 2% to 31% ± 2%, P < .05 and 23% ± 2% to 29% ± 2%, P < .05 in iNO and placebo groups) without any difference between the iNO and placebo groups. The overall incidence of postoperative right ventricular failure was 4 of 47 (8.5%). CONCLUSIONS LVAD implantation markedly improved right ventricular geometry and function in most of the patients, probably by resolving left ventricular congestion and thus reducing right ventricular afterload. Beneficial effects of iNO may have been masked by more pronounced consequences of left ventricular unloading on right ventricular function.

Patient–prosthesis mismatch after transapical aortic valve implantation: Incidence and impact on survival

OBJECTIVES Transcatheter aortic valve implantation (TAVI) has become an important therapeutic option for high-risk patients with severe aortic valve stenosis. Patient-prosthesis mismatch (P-PM) is an important determinant of morbidity and mortality after open aortic valve replacement. The objective of our study was to evaluate P-PM incidence and its impact on survival in a large cohort of patients treated with TAVI. METHODS AND RESULTS We retrospectively analyzed transesophageal echocardiographic data of 278 consecutive patients (Society of Thoracic Surgeons score 18.5 ± 15.3, age 80 ± 8 years) who underwent transapical TAVI with Edwards Sapien valves between April 2008 and March 2011. Effective orifice area was calculated using the continuity equation and indexed with body surface area (iEOA). P-PM was stratified as severe (iEOA < 0.65 cm(2)/cm(2)) and moderate (iEOA, 0.65-0.85 cm(2)/m(2)). Midterm survival (up to 30 months) was analyzed by Kaplan-Meier curves and log-rank tests. There was no P-PM in 181 (65.1%) patients; moderate P-PM was found in 76 (27.3%) patients and severe P-PM in 21 (7.6%). Thirty-day survival was 96.0%, 97.3%, and 90.5%. The 3-month survival was 91%, 90%, and 66%, respectively (P = .0013). Combination of severe P-PM with peak pressure gradients greater than 10 mm Hg further reduced the 3-month survival to 48%. Additionally, mean survival time in patients with an ejection fraction less than 50% was significantly shorter than in patients with an ejection fraction greater than 50% (20.8 ± 1.5 vs 24.1 ± 0.8 months; P = .027). CONCLUSIONS P-PM is found in patients undergoing transapical TAVI. Severe mismatch is accompanied by high early mortality, especially when combined with increased pressure gradients.

Transcatheter aortic valve implantation combined with elective coronary artery stenting: a simultaneous approach

OBJECTIVES Many patients referred for transcatheter aortic valve implantation (TAVI) also require percutaneous coronary intervention (PCI). The aim of the study was to identify whether combined treatment of patients with aortic stenosis and coronary artery disease (CAD) with TAVI and PCI has comparable results to treatment of patients with no CAD or with CAD with non-significant lesions who receive only TAVI. METHODS Between April 2008 and August 2013, 730 consecutive patients underwent transapical TAVI at our institution. In our study population of 593 patients, 285 (48.1%) had no CAD and received TAVI only (Group I); 232 (39.1%) presented with CAD but no highly significant coronary artery lesion(s) and also received TAVI only (Group II), and 76 (12.8%) had CAD and highly significant coronary lesion(s) and underwent combined, single-staged TAVI and PCI (Group III). Three transapical TAVI patients who received PCI because of iatrogenic coronary artery obstruction during TAVI and 134 transapical TAVI patients with previous CABG were excluded from this study. RESULTS Group II showed a calculated mean SYNTAX score of 5.7 ± 7.4. However, Group III showed a statistically significantly higher mean SYNTAX score of 8.0 ± 5.7 than Group II (P < 0.001) before the combined procedure. Combined TAVI and PCI reduced the mean SYNTAX score significantly from 8.0 ± 5.7 to 3.0 ± 4.9 (P < 0.001) in those patients presenting with severe aortic stenosis and highly significant CAD (Group III). The thirty-day all-cause mortality rate was 5.3, 3.9 and 2.6% for Group I, II and III, respectively (P = 0.609). Patients with highly significant CAD undergoing TAVI and PCI had similar survival up to 3 years as patients without CAD undergoing TAVI only. Radiation time and amount of contrast agent were higher during combined treatment in Group III (P < 0.05). However, no difference in acute kidney injury post-procedurally was observed. CONCLUSIONS Single-stage combined treatment of severe aortic stenosis and highly relevant coronary lesions is a safe and feasible procedure. Early survival and survival up to 3 years are comparable to that observed in patients presenting without CAD who received TAVI only. PCI effectively reduces the complexity of coronary lesions. Although more contrast agent is applied during the combined treatment, the rate of acute kidney injury was not higher.

Trans-apical aortic valve implantation in patients with severe calcification of the ascending aorta

OBJECTIVE In patients with calcification of the ascending aorta, postoperative stroke and mortality rates remain high after conventional aortic valve replacement, but the results of trans-apical aortic valve implantation in these patients are not known. We evaluate the outcome of trans-apical aortic valve implantation in patients with severely calcified ascending aorta in a single center with expanded procedural experience. METHODS Between April 2008 and July 2010, 258 patients underwent trans-apical aortic valve implantation using Edwards Sapien valve. By computed tomography (CT) scan, we identified 46 (18%) patients with severe calcification of the ascending aorta (16 with porcelain aorta and 30 with severe, but not complete, calcification). RESULTS Of 46 patients (mean age 77 ± 10 years, range 63-90 years; EuroSCORE (European System for Cardiac Operative Risk Evaluation) 45 ± 22%; STS (Society of Thoracic Surgeons) score 23 ± 13) with calcified aorta, 15 received 23-mm valves and 31 patients 26-mm valves. Primary valve implantation was successful in 44 patients and a second valve was implanted (valve-in-valve) in two. Six patients underwent concomitant interventions (three elective percutaneous coronary intervention (PCI), one off-pump coronary artery bypass (OPCAB), one tricuspid valve reconstruction, and one left-ventricular (LV) aneurysmectomy). The final procedural results showed valve incompetence (trace or grade 1) in 17 (37%) patients and paravalvular leak in 15 (32.6%) (trace in 10 and grade 1 in five). There was no 30-day mortality. Postoperatively, cranial CT showed new cerebral ischemia areas in three patients (6.2%), but only one patient (2.1%) experienced postoperative neurological deficit (temporary aphasia). Survival at 6 and 12 months was 88% and 85.2%, respectively. CONCLUSIONS Trans-apical aortic valve implantation can be performed safely in patients with aortic valve stenosis and severe calcification of the ascending aorta.

Simultaneous aortic valve replacement in left ventricular assist device recipients: single-center experience

Introduction: Aortic valve regurgitation or the presence of a mechanical aortic valve prosthesis is a relative contraindication for implantation of left ventricular assist devices (LVAD). However, concomitant aortic valve replacement by a biological prosthesis is one of the options in this situation. We analyzed our recent experience with left ventricular assist device implantation and concomitant aortic valve replacement. Methods: Between January 1, 2008 and January 15, 2012, 318 adult patients (>18 years old) were supported with a long-term implantable LVAD in our institution. In 19, simultaneous aortic valve replacement (6 redo and 13 primary procedures) was performed. Patients were divided into 2 groups according to INTERMACS (IM) level: Group 1 (n = 7) consisted of patients with IM level 1–2 and Group 2 (n = 12) of IM level 3–4 patients. As a control cohort we analyzed all LVAD recipients during the study period (n = 299, study group excluded). The control cohort was similarly divided into two groups according to the IM level: Group 3 (n = 162) consisted of patients with IM level 1–2 and Group 4 (n = 137) of those with IM level 3–5. Perioperative data and outcomes in all groups were retrospectively analyzed and compared (Group 1 compared to Group 3; and Group 2 to Group 4). Results: In study Groups 1 and 2 all patients were male; in Groups 3 and 4, 80% and 88% respectively were male. Median age distribution in Groups was 55, 61, 54, and 57 years respectively. Patients from Group 2 were significantly older than those from Group 4 (p = 0.039). Body mass index was significantly lower in Group 1 than in Group 3 (p = 0.033). Cardio-pulmonary bypass time was significantly longer in Groups 1 and 2 compared with Groups 3 and 4 respectively (p≤0.001). Patients from Group 1 had a trend more often to develop right ventricular failure requiring a right ventricular assist device (RVAD) than those in Group 3 (p = 0.09). Intensive care unit stay duration of mechanical ventilation and in-hospital mortality in Group 1 were significantly higher than in Group 3 (p = 0.025, p = 0.005, p = 0.038). Patients from Group 2 had similar outcomes compared to those from Group 4. Conclusions: In stable patients, simultaneous aortic valve replacement and LVAD implantation are not associated with an impaired outcome. In patients with cardiogenic shock an additional aortic valve replacement may impair outcome; therefore alternative techniques should be considered.

Introducing transapical aortic valve implantation (part 1): effect of a structured training program on clinical outcome in a series of 500 procedures.

OBJECTIVES The purpose of the present study was to test whether the cumulative knowledge from the field of transapical transcatheter aortic valve implantation, when incorporated into a structured training and then gradually dispersed by internal proctoring, might eliminate the negative effect of the learning curve on the clinical outcomes. METHODS The present study was a retrospective, single-center, observational cohort study of prospectively collected data from all 500 consecutive high-risk patients undergoing transapical transcatheter aortic valve implantation at our institution from April 2008 to December 2011. Of the 500 patients, 28 were in cardiogenic shock. Differences during the study period in baseline characteristics, procedural and postprocedural variables, and survival were analyzed using different statistical methods, including cumulative sum charts. RESULTS The overall 30-day mortality was 4.6% (95% confidence interval, 3.1%-6.8%) and was 4.0% (95% confidence interval, 2.6%-6.2%) for patients without cardiogenic shock. Throughout the study period, no significant change was seen in the 30-day mortality (Mann-Whitney U test, P = .23; logistic regression analysis, odds ratio, 0.83 per 100 patients; 95% confidence interval, 0.62-1.12; P = .23). Also, no difference was seen in survival when stratified by surgeon (30-day mortality, P = .92). An insignificant change was seen toward improved overall survival (hazard ratio, 0.90 per 100 patients; 95% confidence interval, 0.77-1.04; P = .15). CONCLUSIONS The structured training program can be used to introduce transapical transcatheter aortic valve implantation and then gradually dispersed by internal proctoring to other members of the team with no concomitant detriment to patients.