The prognostic implications of preexisting atrial fibrillation (AF) and new-onset AF (NOAF) in transcatheter aortic valve implantation (TAVI) remain uncertain. This study assesses the epidemiology of AF in patients treated with TAVI and evaluates their outcomes according to the presence of preexisting AF or NOAF. A retrospective analysis of 708 patients undergoing TAVI from 2 heart hospitals was performed. Patients were divided into 3 study groups: sinus rhythm (n = 423), preexisting AF (n = 219), and NOAF (n = 66). Primary outcomes of interest were all-cause death and stroke both at 30-day and at 1-year follow-up. Preexisting AF was present in 30.9% of our study population, whereas NOAF was observed in 9.3% of patients after TAVI. AF and NOAF patients showed a higher rate of 1-year all-cause mortality compared with patients in sinus rhythm (14.6% vs 6.5% for preexisting AF and 16.3% vs 6.5% for NOAF, p = 0.007). No differences in 30-day mortality were observed between groups. In patients with AF (either preexisting and new-onset), those discharged with single antiplatelet therapy displayed higher mortality rates at 1 year (42.9% vs 11.7%, p = 0.006). Preexisting AF remained an independent predictor of mortality at 1-year follow-up (hazard ratio [HR] 2.34, 95% CI 1.22 to 4.48, p = 0.010). Independent predictors of NOAF were transapical and transaortic approach as well as balloon postdilatation (HR 3.48, 95% CI 1.66 to 7.29, p = 0.001; HR 5.08, 95% CI 2.08 to 12.39, p <0.001; HR 2.76, 95% CI 1.25 to 6.08, p = 0.012, respectively). In conclusion, preexisting AF is common in patients undergoing TAVI and is associated with a twofold increased risk of 1-year mortality. This negative effect is most pronounced in patients discharged with single antiplatelet therapy compared with other antithrombotic regimens.
Transcatheter aortic valve implantation (TAVI) is an established treatment for patients with aortic stenosis (AS) who are inoperable or at high risk for surgery. A substantial proportion of patients who are scheduled for TAVI are noted to have atrial fibrillation (AF) at the time of the screening for eligibility for TAVI. Indeed, AF and AS coexist with a prevalence that varies from 16% to 40%. Moreover, new-onset AF (NOAF) is a frequent finding in the postoperative period after TAVI, with an incidence ranging from 0.7% to 31.9%. Population-based studies indicate an increased risk of stroke and systemic embolism as well as impaired long-term survival of subjects with AF compared with those with normal sinus rhythm (SR). In the general population, AF is estimated to increase the risk of death 1.5-fold in men and 1.9-fold in women. AF is a well-established predictor of adverse outcomes in patients with AS, and several previous studies demonstrated increased risk for mortality related to AF in patients undergoing open-chest valve surgery. Similarly, NOAF is associated with overall and late mortality after coronary artery bypass graft, perioperative complications, and 30-day mortality and cerebrovascular events (CVE) in patients with postmyocardial infarction. However, data on the prevalence and impact of preexisting AF or NOAF in the setting of TAVI are scant and limited to retrospective studies that have specifically focused on this issue. In the present study, we sought to evaluate the epidemiology, predictors, management, and prognostic implications of AF, either preexisting or new-onset, in patients who underwent TAVI.
Methods
Data were collected on consecutive patients with severe, symptomatic AS undergoing TAVI at Baylor Heart and Vascular Hospital (Dallas, Texas) and the Heart Hospital Baylor Plano (Plano, Texas) from January 2012 to August 2015. Baseline demographics, procedural data, and clinical outcomes were retrospectively collected and analyzed. For the purpose of the current analysis, data from both medical centers were pooled, and a joint database was created. The study was approved by the Baylor Institutional Review Board.
Preexisting AF was diagnosed based on clinical history and/or on a 12-lead electrocardiogram performed before TAVI. NOAF was defined as any episode of AF occurring within 30 days after TAVI in a patient with no previous known AF, lasting long enough to be recorded on a 12-lead electrocardiogram or at least 30 seconds on a rhythm strip. All study end points were defined according to Valve Academic Research Consortium definitions. The primary outcomes of interest were all-cause death and stroke both at 30-day and at 1-year follow-up. Secondary measures included in-hospital mortality and minor, major, and life-threatening bleedings.
Continuous variables are summarized as mean ± SD or as medians and interquartile range as appropriate and were compared using the Student t test or Mann–Whitney rank-sum test. Categorical variables were compared using the chi-square or the Fisher’s exact test. Binary logistic regression was used for the prediction of NOAF and 1-year all-cause mortality in the whole population as well as in patients with AF, respectively, as dependent variables, whereas baseline variables of clinical interest and/or satisfaction of the entry criterion of p <0.05 in the univariable analysis were used as explanatory variables. Survival curves were constructed using Kaplan–Meier estimates, whereas comparisons relied on the log-rank test. A 2-sided alpha level of 0.05 was used for all superiority testing. All statistical analyses were performed using SPSS (version 19) statistical software (SPSS, Inc., Chicago, Illinois).
Results
The study population consisted of 708 patients who underwent TAVI, divided in 3 study groups: patients in SR up to 30 days after TAVI and without any history of AF (n = 423), patients with preexisting AF (n = 219), and patients with NOAF (n = 66). The baseline characteristics, echocardiographic, and procedural data of these groups are listed in Table 1 . The observed prevalence of preexisting AF (paroxysmal, persistent, or permanent) in our study population was 30.9%. Patients with preexisting AF displayed a higher prevalence of previous CVE, had a lower stroke volume index (SVi), and were significantly older than patients in SR. NOAF was observed in 66 patients (9.3%). A significantly higher incidence of NOAF was observed in patients treated using the transapical, transaortic, or other approaches compared with those treated using the transfemoral approach (23.1%, 28.6%, and 25.0% vs 7.2%, respectively; p <0.001).
| Variable | All patients (n=708) | Sinus Rhythm (n=423) | Pre-existing AF (n=219) | New-Onset AF (n=66) | p |
|---|---|---|---|---|---|
| Baseline characteristics | |||||
| Age (years), mean ± SD | 81.9±7.8 | 80.9±8.3 | 83.4±6.6 | 83.1±7.7 | 0.001 |
| Men | 341 (54.4%) | 231 (54.6%) | 128 (58.4%) | 28 (42.4%) | 0.072 |
| Body Mass Index (kg/m 2 ), median (IQR) | 27.9±12.9 | 28.4±15.9 | 26.8±5.9 | 28.9±8.1 | ns |
| Hypertension | 574 (82.2%) | 352 (84.0%) | 167 (78.0%) | 56 (84.8%) | ns |
| Hyperlipidemia | 481 (69.6%) | 293 (70.9%) | 150 (70.1%) | 39 (60.0%) | ns |
| Diabetes | 265 (40.1%) | 165 (42.0%) | 74 (36.3%) | 26 (40.0%) | ns |
| Chronic kidney disease | 345 (49.6%) | 207 (50.0%) | 109 (50.2%) | 29 (43.9%) | ns |
| End stage renal disease | 22 (3.5%) | 13 (3.5%) | 7 (3.6%) | 2 (3.1%) | ns |
| Coronary artery disease | 475 (68.2%) | 291 (70.3%) | 140 (64.2%) | 44 (67.7%) | ns |
| Peripheral arterial disease | 225 (34.0%) | 140 (35.4%) | 65 (32.0%) | 20 (31.7%) | ns |
| COPD | 132 (20.8%) | 81 (21.4%) | 36 (18.5%) | 15 (23.8%) | ns |
| Previous CABG/PCI | 296 (44.6%) | 176 (44.1%) | 91 (45.3%) | 29 (45.3%) | ns |
| Previous CVE | 124 (19.5%) | 60 (16.1%) | 54 (26.7%) | 10 (15.9%) | 0.007 |
| Echocardiographic findings | |||||
| Left ventricle ejection fraction (%), mean ± SD | 54.6±13.0 | 55.0±13.1 | 53.3±13.1 | 55.7±12.7 | ns |
| Stroke Volume indexed (ml/m 2 ), mean ± SD | 37.6±12.0 | 38.6±12.3 | 34.8±11.4 | 40.8±10.3 | <0.0001 |
| Aortic valve mean gradient (mmHg), mean ± SD | 44.1±13.6 | 44.4±13.5 | 43.3±14.1 | 44.8±12.6 | ns |
| Aortic valve area (cm 2 ), mean ± SD | 0.68±0.18 | 0.69±0.18 | 0.66±0.18 | 0.61±0.18 | 0.054 |
| Procedural characteristics | |||||
| Type of Valve | ns | ||||
| Balloon-expandable | 451 (63.8%) | 264 (62.4%) | 142 (64.8%) | 46 (69.7%) | ns |
| Self-expandable | 256 (36.2%) | 159 (37.6%) | 77 (35.2%) | 20 (30.3%) | ns |
| Approach | <0.0001 | ||||
| Trans-femoral | 610 (86.3%) | 376 (88.9%) | 192 (87.7%) | 43 (65.2%) | |
| Trans-apical | 65 (9.2%) | 33 (7.8%) | 17 (7.8%) | 15 (22.7%) | |
| Trans-aortic | 28 (4.0%) | 11 (2.6%) | 10 (4.6%) | 7 (10.6%) | |
| Subclavian | 4 (0.6%) | 3 (0.7%) | 0 (0.0%) | 1 (1.5%) | |
| Post-operative Drugs | <0.0001 | ||||
| DAPT | 426 (61.0%) | 315(75.2%) | 77 (35.8%) | 34 (53.1%) | |
| OAT | 133 (19.1%) | 25 (6.0%) | 92 (42.8%) | 16 (25.0%) | |
| DAPT+OAT | 40 (5.7%) | 4 (1.0%) | 28 (13.0%) | 8 (12.5%) | |
| Single antiplatelet therapy | 99 (14.2%) | 75 (17.9%) | 18 (8.4%) | 6 (9.4%) | |
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