Rodrigo Bagur

Acute kidney injury following transcatheter aortic valve implantation : predictive factors, prognostic value, and comparison with surgical aortic valve replacement

Aims Very few data exist on the occurrence of acute kidney injury (AKI) associated with transcatheter aortic valve implantation (TAVI). The objectives of the present study were (i) to determine the incidence, predictive factors, and prognostic value of AKI following TAVI, and (ii) to compare the occurrence of AKI in TAVI vs. surgical aortic valve replacement (SAVR) in patients with pre-procedural chronic kidney disease (CKD). Methods and results A total of 213 patients (mean age 82 ± 8 years) undergoing TAVI for the treatment of severe aortic stenosis were included in the study. Acute kidney injury was defined as a reduction of >25% in estimated glomerular filtration rate (eGFR) within 48 h following the procedure or the need for haemodialysis during index hospitalization. Those patients with pre-procedural CKD (eGFR <60 mL/min/1.73 m2, n = 119) were compared with 104 contemporary patients with CKD who underwent isolated SAVR. The incidence of AKI following TAVI was 11.7%, with 1.4% of the patients requiring haemodialysis. Predictive factors of AKI were hypertension (OR: 4.66; 95% CI: 1.04–20.87), chronic obstructive pulmonary disease (OR: 2.64, 95% CI: 1.10–6.36), and peri-operative blood transfusion (OR: 3.47, 95% CI: 1.30–9.29). Twenty-one patients (9.8%) died during index hospitalization, and the logistic EuroSCORE (OR: 1.03 for each increase of 1%; 95% CI: 1.01–1.06) and occurrence of AKI (OR: 4.14, 95% CI: 1.42–12.13) were identified as independent predictors of postoperative mortality. Patients with CKD who underwent TAVI were older, had a higher logistic EuroSCORE and lower pre-procedural eGFR values compared with those who underwent SAVR (P < 0.0001 for all). The incidence of AKI was lower (P = 0.001; P = 0.014 after propensity score adjustment) in CKD patients who underwent TAVI (9.2%, need for haemodialysis: 2.5%) compared with those who underwent SAVR (25.9%, need for haemodialysis: 8.7%). Conclusion Acute kidney injury occurred in 11.7% of the patients following TAVI and was associated with a greater than four-fold increase in the risk of postoperative mortality. Hypertension, chronic obstructive pulmonary disease, and blood transfusion were predictive factors of AKI. In those patients with pre-procedural CKD, TAVI was associated with a significant reduction of AKI compared with SAVR.

Cerebral Embolism Following Transcatheter Aortic Valve Implantation : Comparison of Transfemoral and Transapical Approaches

OBJECTIVES The objective of this study was to compare the incidence of cerebral embolism (CE) as evaluated by diffusion-weighted magnetic resonance imaging (DW-MRI) following transapical (TA) transcatheter aortic valve implantation (TAVI) versus transfemoral (TF) TAVI. BACKGROUND The TA-TAVI approach avoids both the manipulation of large catheters in the aortic arch/ascending aorta and the retrograde crossing of the aortic valve, and this avoidance might lead to a lower rate of CE. METHODS This was a prospective multicenter study including 60 patients who underwent cerebral DW-MRI the day before and within the 6 days following TAVI (TF approach: 29 patients; TA approach: 31 patients). Neurologic and cognitive function assessments were performed at DW-MRI time points. RESULTS The TAVI procedure was performed with the Edwards valve and was successful in all cases but one (98%). A total of 41 patients (68%) had 251 new cerebral ischemic lesions at the DW-MRI performed 4 ± 1 days after the procedure, 19 patients in the TF group (66%) and 22 patients in the TA group (71%; p = 0.78). Most patients (76%) with new ischemic lesions had multiple lesions (median number of lesions per patient: 3, range 1 to 31). There were no differences in lesion number and size between the TF and TA groups. No baseline or procedural factors were found to be predictors of new ischemic lesions. The occurrence of CE was not associated with a measurable impairment in cognitive function, but 2 patients (3.3%) had a clinically apparent stroke within the 24 h following the procedure (1 patient in each group). CONCLUSIONS TAVI is associated with a high rate of silent cerebral ischemic lesions as evaluated by DW-MRI, with no differences between the TF and TA approaches. These results provide important novel insight into the mechanisms of CE associated with TAVI and support the need for further research to both reduce the incidence of CE during these procedures and better determine their clinical relevance.

Comparison Between Transcatheter and Surgical Prosthetic Valve Implantation in Patients With Severe Aortic Stenosis and Reduced Left Ventricular Ejection Fraction

Background— Patients with severe aortic stenosis and reduced left ventricular ejection fraction (LVEF) have a poor prognosis with conservative therapy but a high operative mortality when treated surgically. Recently, transcatheter aortic valve implantation (TAVI) has emerged as an alternative to surgical aortic valve replacement (SAVR) for patients considered at high or prohibitive operative risk. The objective of this study was to compare TAVI and SAVR with respect to postoperative recovery of LVEF in patients with severe aortic stenosis and reduced LV systolic function. Methods and Results— Echocardiographic data were prospectively collected before and after the procedure in 200 patients undergoing SAVR and 83 patients undergoing TAVI for severe aortic stenosis (aortic valve area ≤1 cm2) with reduced LV systolic function (LVEF ≤50%). TAVI patients were significantly older (81±8 versus 70±10 years; P<0.0001) and had more comorbidities compared with SAVR patients. Despite similar baseline LVEF (34±11% versus 34±10%), TAVI patients had better recovery of LVEF compared with SAVR patients (&Dgr;LVEF, 14±15% versus 7±11%; P=0.005). At the 1-year follow-up, 58% of TAVI patients had a normalization of LVEF (>50%) as opposed to 20% in the SAVR group. On multivariable analysis, female gender (P=0.004), lower LVEF at baseline (P=0.005), absence of atrial fibrillation (P=0.01), TAVI (P=0.007), and larger increase in aortic valve area after the procedure (P=0.01) were independently associated with better recovery of LVEF. Conclusion— In patients with severe aortic stenosis and depressed LV systolic function, TAVI is associated with better LVEF recovery compared with SAVR. TAVI may provide an interesting alternative to SAVR in patients with depressed LV systolic function considered at high surgical risk.

Incidence, predictive factors, and prognostic value of new-onset atrial fibrillation following transcatheter aortic valve implantation.

OBJECTIVES This study sought to evaluate the incidence, predictive factors, and prognostic value of new-onset atrial fibrillation (NOAF) following transcatheter aortic valve implantation (TAVI). BACKGROUND Very few data exist on the occurrence of NOAF following TAVI. METHODS A total of 138 consecutive patients with no prior history of atrial fibrillation (AF) underwent TAVI with a balloon-expandable valve. Patients were on continuous electrocardiogram monitoring until hospital discharge, and NOAF was defined as any episode of AF lasting >30 s. All clinical, echocardiographic, procedural, and follow-up data were prospectively collected. RESULTS NOAF occurred in 44 patients (31.9%) at a median time of 48 h (interquartile range: 0 to 72 h) following TAVI. The predictive factors of NOAF were left atrial (LA) size (odds ratio [OR]: 1.21 for each increase in 1 mm/m(2), 95% confidence interval [CI]: 1.09 to 1.34, p < 0.0001) and transapical approach (OR: 4.08, 95% CI: 1.35 to 12.31, p = 0.019). At 30-day follow-up, NOAF was associated with a higher rate of stroke/systemic embolism (13.6% vs. 3.2%, p = 0.021, p = 0.047 after adjustment for baseline differences between groups), with no differences in mortality rate between groups (NOAF: 9.1%, no-NOAF: 6.4%, p = 0.57). At a median follow-up of 12 months (interquartile range: 5 to 20 months), a total of 27 patients (19.6%) had died, with no differences between the NOAF (15.9%) and no-NOAF (21.3%) groups, p = 0.58. The cumulative rate of stroke and stroke/systemic embolism at follow-up were 13.6% and 15.9%, respectively, in the NOAF group versus 3.2% in the no-NOAF group (p = 0.039, adjusted p = 0.037 for stroke; p = 0.020, adjusted p = 0.023 for stroke/systemic embolism). CONCLUSIONS NOAF occurred in about one-third of the patients with no prior history of AF undergoing TAVI and its incidence was increased in patients with larger LA size and those undergoing transapical TAVI. NOAF was associated with a higher rate of stroke/systemic embolism, but not a higher mortality, at 30 days and at 1-year follow-up.

Transcatheter Aortic Valve Replacement: Outcomes of Patients With Moderate or Severe Mitral Regurgitation

OBJECTIVES The aim of this study was to evaluate the impact of mitral regurgitation (MR) on outcomes after transcatheter aortic valve replacement (TAVR) and the impact of TAVR on MR. BACKGROUND Little is known of the influence of MR on outcomes after TAVR. METHODS The outcomes of patients with mild or less (n = 319), moderate (n = 89), and severe (n = 43) MR were evaluated after TAVR at 2 Canadian centers. RESULTS Patients with moderate or severe MR had a higher mortality rate than those with mild or less MR during the 30 days after TAVR (adjusted hazard ratio: 2.10; 95% confidence interval: 1.12 to 3.94; p = 0.02). However, the mortality rates after 30 days were similar (adjusted hazard ratio: 0.82; 95% confidence interval: 0.50 to 1.34; p = 0.42). One year after TAVR, moderate MR had improved in 58%, remained moderate in 17%, and worsened to severe in 1%, and 24% of patients had died. Severe MR had improved in 49% and remained severe in 16%, and 35% of patients had died. Multivariate predictors of improved MR at 1 year (vs. unchanged MR, worse MR, or death) were a mean transaortic gradient ≥ 40 mm Hg, functional (as opposed to structural) MR, the absence of pulmonary hypertension, and the absence of atrial fibrillation. CONCLUSIONS Moderate or severe MR in patients undergoing TAVR is associated with a higher early, but not late, mortality rate. At 1-year follow-up, MR was improved in 55% of patients with moderate or severe MR at baseline. Improvement was more likely in patients with high transaortic gradients, with functional MR, without pulmonary hypertension and without atrial fibrillation.

Electrocardiographic changes and clinical outcomes after transapical aortic valve implantation

BACKGROUND Transapical aortic valve implantation (TAVI) for the treatment of severe aortic stenosis requires the insertion of a large catheter through the left ventricular apex. However, the electrocardiographic (ECG) changes associated with the incision and repair of the left ventricular apex and the potential damage to the conduction system caused by implanting a balloon-expandable valve in aortic position are not known. The objective of our study was to determine the incidence, type, and timing of ECG changes associated with TAVI. METHODS The standard 12-lead ECGs of 33 consecutive patients (mean age 81 +/- 9 years, 13 men) diagnosed with symptomatic severe aortic stenosis (valve area 0.62 +/- 0.16 cm(2)) who underwent TAVI with an Edwards-SAPIEN valve were analyzed at baseline (within 24 hours before the procedure), immediately (within 6 hours) after the procedure, at hospital discharge, and at 1-month follow-up. RESULTS There were no procedural deaths, and 30-day mortality was 6%. The incidence of complete left ventricular branch block (LBBB) and left anterior hemiblock (LAHB) increased from 9% and 3% at baseline to 27% and 36% after the procedure, respectively (P < .03 for both). A lower (ventricular) position of the valve relative to the hinge point of the anterior mitral leaflet was associated with a higher incidence of new LBBB (35% vs 0%, P = .029); and a greater valve size-aortic annulus ratio, with the occurrence of new LAHB (1.20 +/- 0.07 vs 1.14 +/- 0.06, P = .021). At 1-month follow-up, the rate of LBBB and LAHB decreased to 13% and 10%, respectively (P = not significant compared with baseline). There were no cases of new atrioventricular block, and no patient needed pacemaker implantation. Transient (<48 hours) ST-elevation changes, mostly in the anterior and/or lateral leads, occurred in 6 patients (18%) immediately after the procedure; but only 1 of these patients presented new Q waves at 1-month follow-up. CONCLUSIONS Transapical aortic valve implantation was associated with a significant but transient (<1 month) increase in LBBB and LAHB, with no patient requiring pacemaker implantation. These changes were partially related to both lower (more ventricular) valve positioning and greater valve oversizing. Transient (<48 hours) ST-segment elevation changes occurred in about one fifth of the patients after the procedure, but only a minority developed new Q waves in the ECG.

Usefulness of TEE as the Primary Imaging Technique to Guide Transcatheter Transapical Aortic Valve Implantation

OBJECTIVES The aim of this study was to: 1) determine the usefulness of transesophageal echocardiography (TEE) as the primary technique to guide transapical (TA) transcatheter aortic valve implantation (TAVI); and 2) to compare TEE with angiography as the primary imaging modality for TA-TAVI guidance. BACKGROUND TEE has been routinely used as an adjunct to angiography during TA-TAVI procedures, but very few data exist on the use of TEE as the primary imaging technique guiding TA-TAVI. METHODS One hundred consecutive high-risk patients (mean age 79 ± 9 years, mean logistic EuroSCORE: 25.8 ± 17.6%) who underwent TA-TAVI in our center were included. The Edwards valve was used in all cases, and all procedures were performed in an operating room without hybrid facilities. The TA-TAVI was primarily guided by angiography in the first 25 patients (A-TAVI group) and by TEE in the last 75 patients (TEE-TAVI group). Procedural, 30-day, and follow-up results were evaluated. RESULTS No differences were observed between groups at baseline except for a higher (p = 0.001) prevalence of moderate or severe mitral regurgitation in the TEE-TAVI group. The procedure was successful in 97.3% and 100% of the patients in the TEE-TAVI and A-TAVI groups, respectively (p = 1.0), and a lower contrast volume was used in the TEE-TAVI group (12 [5 to 20] ml vs. 40 [20 to 50] ml, p < 0.0001). There were no differences between groups in the occurrence of valve malposition needing a second valve (TEE-TAVI: 5.3%; A-TAVI: 4%; p = 1.0) or valve embolization (TEE-TAVI: 1.3%; A-TAVI: 4%; p = 0.44). The results regarding post-procedural valve hemodynamic status and aortic regurgitation were similar between groups. The survival rates at 30-day and 1-year follow-up were 87% and 75% in the TEE-group and 88% and 84% in the A-TAVI group, respectively (log-rank = 0.49). CONCLUSIONS TEE-TAVI was associated with similar acute and midterm results as A-TAVI and significantly reduced contrast media use during the procedures. These results suggest the feasibility and safety of performing TA-TAVI procedures in an operating room without hybrid facilities, but larger studies are needed to confirm these findings.

Need for permanent pacemaker as a complication of transcatheter aortic valve implantation and surgical aortic valve replacement in elderly patients with severe aortic stenosis and similar baseline electrocardiographic findings.

OBJECTIVES The aim of this study was to compare the incidence and predictive factors of complete atrioventricular block (AVB) and permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI) versus surgical aortic valve replacement (SAVR). BACKGROUND No data exist on the need for PPI after TAVI versus SAVR in patients with similar baseline electrocardiographic (ECG) findings. METHODS A total of 411 patients with severe aortic stenosis (AS) and no prior pacemaker who underwent TAVI with the balloon-expandable Edwards valve (Edwards Lifesciences, Irvine, California) were matched (1:1) with 411 elderly patients with severe AS who underwent isolated SAVR on the basis of baseline ECG findings. The incidence, reasons, and predictive factors for PPI within 30 days after the procedure were compared between groups. RESULTS Mean age was similar in both groups (p = 0.11), and the TAVI group had a higher Society of Thoracic Surgeons score (p < 0.001). The rate of new PPI was higher after TAVI (7.3%) compared with SAVR (3.4%), p = 0.014. Complete AVB and severe symptomatic bradycardia, respectively, were the reasons for PPI in the TAVI (5.6% and 1.7%, respectively) and SAVR (2.7% and 0.7%, respectively) groups (p = 0.039 for complete AVB, p = NS for symptomatic bradycardia). The presence of baseline right bundle branch block was the only variable associated with PPI in the TAVI group (odds ratio: 8.61, 95% confidence interval: 3.14 to 23.67, p < 0.0001), whereas no variable was found in the SAVR group. CONCLUSIONS Transcatheter aortic valve implantation was associated with a higher rate of complete AVB and PPI compared with SAVR in elderly patients with severe AS and similar baseline ECG findings. The presence of baseline right bundle branch block correlated with the need for PPI in the TAVI group.

Validation and Characterization of Transcatheter Aortic Valve Effective Orifice Area Measured by Doppler Echocardiography

OBJECTIVES The objectives were to compare different Doppler echocardiographic methods for the measurement of prosthetic valve effective orifice area (EOA) following transcatheter aortic valve implantation (TAVI) and to determine the factors influencing the EOA of transcatheter balloon expandable valves. BACKGROUND Previous studies have used different methods for the measurement of the valve EOA following TAVI. Factors influencing the EOA of transcatheter valves are unknown. METHODS A total of 122 patients underwent TAVI with the use of the Edwards-SAPIEN valve (Edwards Lifesciences, Irvine, California). The EOA was measured by transthoracic echocardiography at hospital discharge, 6 months and 1 year after TAVI with the use of 2 methods as described in previous studies. In Method #1 (EOA(1)), LVOT diameter (LVOTd) entered in the continuity equation was measured at the base of prosthesis cusps whereas, in Method #2 (EOA(2)), LVOTd was measured immediately proximal to the prosthesis stent. RESULTS The average EOA(2) (1.57 ± 0.41 cm(2)) was larger (p < 0.01) than the EOA(1) (1.21 ± 0.38 cm(2)). Accordingly, incidence of severe PPM (indexed EOA ≤0.65 cm(2)/m(2)) was 3-fold lower with the use of EOA(2) than with EOA(1) (9% vs. 33%; p < 0.001). Mean transprosthetic gradient correlated better (p = 0.03) with indexed EOA(2) (r = -0.70, p < 0.0001) than with indexed EOA(1) (r = -0.58, p < 0.0001). Intraobserver and interobserver variability were lower for EOA(2) compared to EOA(1) (intra: 5% vs. 7%, p = 0.06; inter: 6% vs. 14%; p < 0.001). Aortic annulus size was the sole independent determinant (p = 0.01) of prosthetic valve EOA(2). The average EOA varied from 1.37 ± 0.23 cm(2) for aortic annulus size <19 mm up to 1.90 ± 0.17 cm(2) for size >23 mm. CONCLUSIONS When estimating the EOA of Edwards-SAPIEN valves by Doppler-echocardiography, it is recommended to use the LVOT diameter and velocity measured immediately proximal to the stent. The main determinant of the EOA of transcatheter valves is the patients annulus size and these valves provide excellent hemodynamics even in patients with a small aortic annulus.

Transcatheter Aortic Valve Implantation in Patients With Severe Aortic Stenosis and Small Aortic Annulus

OBJECTIVES Valve hemodynamics and clinical outcomes among patients with a small aortic annulus who underwent transcatheter aortic valve implantation (TAVI) were examined. BACKGROUND The presence of a small aortic annulus may complicate the surgical management of patients with severe aortic stenosis (AS). TAVI is an alternative to aortic valve replacement (AVR) in high-risk patients, but few data exist on the results of TAVI in patients with a small aortic annulus. METHODS Between 2007 and 2010, 35 patients (mean age 79.2 ± 9.4 years) with severe AS and an aortic annulus diameter <20 mm (mean 18.5 ± 0.9 mm) underwent TAVI with a 23-mm Edwards SAPIEN bioprosthesis (Edwards Lifesciences, Inc., Irvine, California). Echocardiographic parameters and clinical outcomes were assessed prior to discharge and at 6, 12, and 24 months. RESULTS Procedural success was achieved in 34 patients (97.1%). There was 1 in-hospital death. Peak and mean transaortic gradients decreased from 76.3 ± 33.0 mm Hg and 45.2 ± 20.6 mm Hg at baseline to 21.8 ± 8.4 mm Hg and 11.7 ± 4.8 mm Hg post-procedure, respectively, both p < 0.0001. Mean indexed effective orifice area (IEOA) increased from 0.35 ± 0.10 cm(2)/m(2) at baseline to 0.90 ± 0.18 cm(2)/m(2) post-procedure, p < 0.0001. Severe prosthesis-patient mismatch (IEOA <0.65 cm(2)/m(2)) occurred in 2 patients (5.9%). At a mean follow-up of 14 ± 11 months, gradients remained low and 30 of the 31 remaining survivors were in New York Heart Association functional class I or II. CONCLUSIONS In high-risk patients with severe AS and a small aortic annulus, TAVI is associated with good post-procedural valve hemodynamics and clinical outcomes. TAVI may provide a reasonable alternative to conventional AVR in elderly patients with a small aortic annulus.