Transcatheter aortic valve implantation (TAVI) is an emerging technique for the treatment of severe symptomatic aortic stenosis. Little has been reported about the use of different devices and multiple catheter-based options and anesthetic techniques in the same institution. We report the long-term clinical experience in treating patients with severe symptomatic aortic stenosis using TAVI. We analyzed the outcomes of 153 TAVI-treated patients who were followed for ≤2 years. All patients were at very high risk of surgical valve replacement. The Medtronic-CoreValve device was used in 59.5% and the Edwards-SAPIEN device in 40.5% of the patients. The primary end point was death from any cause during follow-up. The mean ± SD patient age was 81.1 ± 6 years, and 62% of the patients were women. The procedural success rate was 97.4%. At 30 days of follow-up, the all-cause mortality was 3.9%. Two-year follow-up data were obtained for 108 patients, with 85.5% survival of treated patients. The 30-day stroke rate was 3.9%. No significant differences in mortality were found when angioplasty was performed before or during TAVI compared with TAVI alone. Multivariate analysis showed that increased baseline creatinine (hazard ratio 1.55, 95% confidence interval 1.01 to 2.42, p = 0.049) and increased logistic European System for Cardiac Operative Risk Evaluation score (hazard ratio 1.03, 95% confidence interval 1.01 to 1.06, p = 0.048) predicted all-cause mortality. In conclusion, the clinical outcome of TAVI is favorable. The use of both procedural devices and multiple techniques in the same institution is feasible and potentially desirable.
Aortic stenosis (AS) is the most frequent contemporary valve disease. Transcatheter aortic valve implantation (TAVI) has become a consolidated alternative for the successful treatment of high-risk patients with AS. A large amount of data regarding early- and intermediate-term clinical outcomes after TAVI have been published. Less is known about the long-term follow-up of these “all comer” patients. Thus, we aimed to report our initial long-term clinical experience with TAVI for “all comer” patients with severe symptomatic AS using currently approved devices.
Methods
From November 2008 to March 2012, 367 patients with severe and symptomatic AS were referred to a dedicated consultation “heart team” forum in our medical center. This forum included a multidisciplinary team of cardiologists, cardiac surgeons, and other professionals. To determine the appropriate treatment for each patient, the patients went through a rigorous assessment process. Severe AS was defined as a valvular orifice area <1.0 cm 2 or <0.6 cm 2 /m 2 and/or the mean transaortic valvular gradient >40 mm Hg and/or jet velocity >4.0 m/s. All patients considered for valve replacement were assessed by coronary and peripheral angiography, and all patients selected for TAVI underwent transesophageal echocardiography. Vascular access was assessed by multislice computed tomography angiography, as required. Both the logistic European System for Cardiac Operative Risk Evaluation score (log EuroScore) and Society of Thoracic Surgeons score were calculated and determined before the TAVI procedure and certainly within 4 weeks before the index procedure.
Patients with an estimated life expectancy of <12 months or cognitive deterioration were referred for medical treatment and/or balloon aortic valvuloplasty. Patients who were candidates for valve replacement with an acceptable operative risk, defined as a log EuroScore <15% and a Society of Thoracic Surgeons score <8%, were mostly assigned to surgical aortic valve replacement. Patients with a log EuroScore >15% and a Society of Thoracic Surgeons score >8% were evaluated individually and often referred for TAVI.
Catheter access selection was performed using the following criteria. Patients with iliac femoral vessels ≥6 mm were considered suitable for 18F transfemoral catheter access. In all but 4 femoral cases, ProStar (Abbot Vascular, Santa Clara, California) suturing was used. Patients in whom transfemoral access was not suitable were assessed for left transaxillary access, transapical, and, finally, transaortic access.
Our center used both available transcatheter aortic valve devices. The Edwards-SAPIEN system (Edwards Lifesciences, Irvine, California) consists of a balloon-expandable, stainless-steel/cobalt chromium stent (SAPIEN or SAPIEN XT, respectively) housing a bovine pericardial valve within a deflectable catheter. The Edwards-SAPIEN 23-mm and 26-mm valves with the 22F and 24F delivery systems were used from 2008 to 2009. In 2010, we switched to the Edwards-SAPIEN XT 23-mm and 26-mm valves with the 18F or 19F delivery systems. Transapical procedures were performed with the Ascendra delivery system 28F sheath and, since 2010, the Ascendra II 22F sheath.
The Medtronic CoreValve prosthesis (Medtronic, Minneapolis, Minnesota) consists of a trileaflet porcine pericardial tissue valve mounted in a self-expanding nitinol stent. Since July 2010, third-generation prostheses with the AccuTrak stability layer have been used.
The characteristics favoring Medtronic CoreValve implantation were large aortic valve annulus, a transaxillary approach, borderline femoral size, and aortic regurgitation (AR). The characteristics favoring Edwards-SAPIEN implantation were annulus size of 18 to 21 mm, a transapical approach, and conduction abnormalities.
All TAVI procedures were performed in our catheterization suite by interventional cardiologists. Transesophageal echocardiography was performed during the TAVI procedure in 34% of the patients. After initial balloon valvuloplasty, the balloon catheter with the bioprosthetic valve crimped onto it was inserted. Rapid right ventricular pacing was performed during deployment of the Edwards-SAPIEN valve and only occasionally during Medtronic-CoreValve implantation. The C-THV Paieon guidance system (Paieon, Rosh Ha’ayim, Israel) was used often for optimal positioning of the implanted valve.
The TAVI procedure was considered successful if the implanted valve was in the appropriate location and functioning properly in the absence of any major complications according to the Valve Academic Research Consortium 1 definitions. The institutional review board approved the data management for the present study.
The primary end point of the present study was death from any cause after TAVI. The secondary end points were death from cardiovascular causes, changes in the New York Heart Association functional class, the immediate and long-term performance of the valve, the presence of residual AR and its grade, and clinically apparent stroke after the TAVI procedure. We also report the results of an analysis between the outcomes of patients treated by TAVI with and without associated coronary artery disease. All patients were prospectively examined at 30 days and 6, 12, and 24 months postoperatively. A 100% follow-up rate was achieved during the assigned period.
All TAVI-related data were registered in an electronic file and analyzed using the SPSS, version 19.0, software (SPSS, Chicago, Illinois). Numeric values are presented as the mean ± SD and categorical variables as percentages. The outcomes of the patients treated using TAVI and percutaneous coronary intervention (PCI) for associated significant coronary artery disease were compared to the outcomes of patients treated by TAVI alone using the Kaplan-Meier method. Survival in the 2 groups was compared using the log-rank test. Univariate and multivariate Cox regression analyses was applied to assess the independent predictors of all-cause mortality. The multivariate analysis was performed using the predictors found to be significant on univariate analysis. p Values <0.05 were considered significant.
Results
A total of 367 patients with severe AS were referred to our consultation forum. The present study focused on the outcomes of the 153 patients assigned to TAVI. The mean and median follow-up period was 454 and 472 days, respectively.
The patient characteristics and echocardiographic findings are listed in Table 1 . The procedural details and outcomes are listed in Table 2 . Pacemaker implantation after TAVI was required in 23 patients (15.0%): 23% and 3.2% of patients treated with the Medtronic-CoreValve and Edwards-SAPIEN valve, respectively.
| Variable | Value |
|---|---|
| Age (yrs) | 82.1 ± 6.0 |
| Men | 58 (37.9%) |
| Body mass index (kg/m 2 ) | 26.2 ± 5.1 |
| Diabetes mellitus | 45 (29.4%) |
| Hypertension | 138 (90.2%) |
| Dyslipidemia ∗ | 132 (86.2%) |
| Mean glomerular filtration rate † | 66.5 ± 27.3 |
| Glomerular filtration rate <90 ml/min/1.73 m 2 | 110 (71.9%) |
| Glomerular filtration rate 60-89 ml/min/1.73 m 2 | 50 (32.6%) |
| Glomerular filtration rate 30-59 ml/min/1.73 m 2 | 53 (34.6%) |
| Glomerular filtration rate 15-29 ml/min/1.73 m 2 | 4 (2.6%) |
| Glomerular filtration rate <15 ml/min/1.73 m 2 | 3 (1.9%) |
| Previous stroke or transient ischemic attack | 28 (18.3%) |
| Peripheral vascular disease | 31 (20.3%) |
| Anemia ‡ | 91 (59.4%) |
| Chronic obstructive pulmonary disease | 43 (28.1%) |
| “Porcelain” aorta | 11 (7.2%) |
| Pacemaker | 10 (6.5%) |
| Paroxysmal atrial fibrillation | 41 (26.8%) |
| Previous coronary bypass surgery | 38 (24.8%) |
| Previous coronary angioplasty | 44 (28.7%) |
| Previous myocardial infarction | 11 (7.2%) |
| Society of Thoracic Surgeons score | 9.2 ± 5.3% |
| Logistic European System for Cardiac Operative Risk Evaluation score | 22.5 ± 13.2% |
| New York Heart Association functional class II | 4 (2.6%) |
| New York Heart Association functional class III | 100 (65.3%) |
| New York Heart Association functional class IV | 49 (32.1%) |
| Hospitalization in previous 6 months | 83 (54.2%) |
| Maximal aortic valve gradient (mm Hg) | 79.8 ± 22.6 |
| Mean aortic valve gradient (mm Hg) | 50.5 ± 15.4 |
| Mean aortic valve area (cm 2 ) | 0.62 ± 0.16 |
| Mean annulus diameter (mm) | 21.5 ± 1.6 |
| Moderate or severe systolic left ventricular dysfunction | 18 (11.4%) |
| Pulmonary pressure (mm Hg) | 38.5 ± 14.2 |
| Moderate or severe mitral regurgitation | 52 (33.1%) |
∗ Dyslipidemia was defined as total cholesterol >200 mg/dl, low-density lipoprotein >130 mg/dl, high-density lipoprotein <40 mg/dl, and/or triglycerides >200 mg/dl.
† Glomerular filtration rate was calculated by the Modification of Diet in Renal Disease formula.
‡ Anemia was defined as hemoglobin <12 mg/dl for women and <13 mg/dl for men.
| Variable | Value |
|---|---|
| Safety and efficacy end points | |
| Death | |
| At 30 days | 6 (3.9%) |
| From non-cardiac causes | 0 (0%) |
| From cardiovascular cause | 6 (3.9%) |
| At 6 months | 11 (7.1%) |
| From non-cardiac causes | 4 (2.6%) |
| From cardiovascular cause | 7 (4.5%) |
| At 1 year | 14 (9.1%) |
| From non-cardiac causes | 7 (4.5%) |
| From cardiovascular cause | 7 (4.5%) |
| At 2 yrs | 18 (11.7%) |
| From non-cardiac causes | 11 (7.1%) |
| From cardiovascular cause | 7 (4.5%) |
| Periprocedural myocardial infarction | 0 (0%) |
| Major ischemic stroke at 30 days | 6 (3.9%) |
| Life-threatening bleeding | 2 (1.3%) |
| Major bleeding | 2 (1.3%) |
| Minor bleeding | 6 (3.9%) |
| Need for blood transfusion within index hospitalization | 24 (15.6%) |
| Acute kidney injury within index hospitalization | 8 (5.2%) |
| Vascular complications | 27 (17.6%) |
| Major | 2 (1.3%) |
| Minor | 21 (16.3%) |
| Prosthetic valve performance | |
| Aortic stenosis | 0 (0%) |
| Aortic regurgitation | |
| Moderate or greater immediately after procedure | 9 (5.9%) |
| Moderate or greater at 1 month | 4 (2.6%) |
| Moderate or greater at 1 year | 3 (1.9%) |
| Moderate or greater at 2 yrs | 4 (2.6%) |
| Prosthetic valve-associated complications | |
| Conduction disturbances | |
| New onset left bundle branch block | 39 (25.5%) |
| New onset atrial fibrillation | 11 (7.2%) |
| New pacemaker | 23 (15.0%) |
| Coronary obstruction | 0 (0%) |
| Other prosthesis-related adverse events | 0 (0%) |
| Clinical benefit end points | |
| Hospitalization for symptoms of cardiac decompensation ∗ | 11 (7.2%) |
| Therapy-specific end points | |
| Conversion to open surgery | 2 (1.3%) |
| Ventricular perforation with tamponade | 1 (0.6%) |
| Post-transcatheter aortic valve implantation balloon dilation | 22 (14.4%) |
| Implantation of 2 valves or “valve in valve” | 3 (1.9%) |
| Valve retrieval | 4 (2.6%) |
| Valve reintervention | 1 (0.6%) |
| Composite end points | |
| Device success | 149 (97.4%) |
| Combined safety end point at 30 days | 11 (7.2%) |
| Combined efficacy end point at 1 yr | 19 (12.4%) |
| Combined efficacy end point at 2 yrs | 23 (15.0%) |
| Hospital stay (days) | 5.2 ± 4.2 |
| Anesthesia type | |
| Local plus sedation | 103 (67.3%) |
| General anesthesia | 50 (32.6%) |
| Implanted valve type | |
| Medtronic CoreValve | 91 (59.5%) |
| 26-mm Diameter | 51 (33.3%) |
| 29-mm Diameter | 37 (24.2%) |
| 31-mm Diameter | 3 (1.9%) |
| Edwards-SAPIEN | 62 (40.5%) |
| 23-mm Diameter | 36 (23.5%) |
| 26-mm Diameter | 26 (17.0%) |
| Access type | |
| Transfemoral | 112 (73.2%) |
| Transapical | 27 (17.6%) |
| Transaxillary | 13 (8.5%) |
| Transaortic | 1 (0.6%) |
Of the 153 patients initially included in our study, 18 died during the 2-year follow-up period. Of these patients, 7 (4.5%) died from cardiovascular causes, mostly heart failure and procedure-related events, The calculated 1- and 2-year survival was 90.6% (95% confidence interval [CI] 84.8% to 94.6%) and 85.5% (95% CI 80.9% to 92.7%), respectively. The overall Kaplan-Meier survival curve is depicted in Figure 1 .
Patients in whom transfemoral access or transaxillary access was used had a nonsignificant lower mortality rate than patients in whom transapical or transaortic access was used (10.4% vs 17.8%, p = 0.2). This difference resulted from a reduction in cardiovascular mortality (3.2% vs 10.7%, p = 0.1). No differences in noncardiovascular mortality rates were seen between these groups (7.2% vs 7.1%, p = 0.7).
After TAVI, the aortic valve area increased from a mean 0.62 ± 0.16 cm 2 to 1.7 ± 0.19 cm 2 . A significant and sustained decrease in the maximum and mean transaortic valve gradients was observed immediately after valve deployment (from 79.8 ± 22.6 to 13.0 ± 6.03 mm Hg [p >0.01] and from 50.5 ± 15.4 to 8.1 ± 10.1 mm Hg [p >0.01], respectively; Figure 2 ).
Of the 153 treated patients, 130 (84.9%) had some degree of AR before TAVI; 61 (39.8%) had mild AR, 46 (30.0%) mild to moderate AR, 16 (10.4%) moderate AR, 3 (1.9%) moderate to severe AR, and 4 (2.6%) patients severe AR. Immediately after and within 30 days of TAVI, 81 patients (52.9%) had some degree of AR, 68 (44.4%) had mild AR, 11 (7.1%) moderate AR, and 2 (1.3%) moderate to severe AR. After TAVI, the patients reported sustained symptomatic improvement ( Figure 3 ).
During angiographic assessment for TAVI, 36 patients (23.5%) had concomitant significant coronary artery disease. These patients were treated with PCI either before or during the TAVI procedure. The patients who underwent PCI, in addition to TAVI, had had more previous PCI procedures (p = 0.001). No significant differences in mortality were observed for PCI performed before or during TAVI compared to TAVI alone (p = 0.67; Figure 4 ).
