Tamim Nazif

Predictors and Clinical Outcomes of Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement: The PARTNER (Placement of AoRtic TraNscathetER Valves) Trial and Registry

OBJECTIVES The purpose of this study was to identify predictors and clinical implications of permanent pacemaker (PPM) implantation after transcatheter aortic valve replacement (TAVR). BACKGROUND Cardiac conduction disturbances requiring PPM are a frequent complication of TAVR. However, limited data is available regarding this complication after TAVR with a balloon-expandable valve. METHODS The study included patients without prior pacemaker who underwent TAVR in the PARTNER (Placement of AoRtic TraNscathetER Valves) trial and registry and investigated predictors and clinical effect of new PPM. RESULTS Of 2,559 TAVR patients, 586 were excluded due to pre-existing PPM. A new PPM was required in 173 of the remaining 1,973 patients (8.8%). By multivariable analysis, predictors of PPM included right bundle branch block (odds ratio [OR]: 7.03, 95% confidence interval [CI]: 4.92 to 10.06, p < 0.001), prosthesis diameter/left ventricular (LV) outflow tract diameter (for each 0.1 increment, OR: 1.29, 95% CI: 1.10 to 1.51, p = 0.002), LV end-diastolic diameter (for each 1 cm, OR: 0.68, 95% CI: 0.53 to 0.87, p = 0.003), and treatment in continued access registry (OR: 1.77, 95% CI: 1.08 to 2.92, p = 0.025). Patients requiring PPM had a longer mean duration of post-procedure hospitalization (7.3 ± 2.7 days vs. 6.2 ± 2.8 days, p = 0.001). At 1 year, new PPM was associated with significantly higher repeat hospitalization (23.9% vs. 18.2%, p = 0.05) and mortality or repeat hospitalization (42.0% vs. 32.6%, p = 0.007). There was no difference between groups in LV ejection fraction at 1 year. CONCLUSIONS PPM was required in 8.8% of patients without prior PPM who underwent TAVR with a balloon-expandable valve in the PARTNER trial and registry. In addition to pre-existing right bundle branch block, the prosthesis to LV outflow tract diameter ratio and the LV end-diastolic diameter were identified as novel predictors of PPM after TAVR. New PPM was associated with a longer duration of hospitalization and higher rates of repeat hospitalization and mortality or repeat hospitalization at 1 year. (THE PARTNER TRIAL: Placement of AoRtic TraNscathetER Valves Trial; NCT00530894).

Aortic annular sizing using a novel 3-dimensional echocardiographic method: use and comparison with cardiac computed tomography.

Background—Previous studies have shown cross-sectional 3-dimensional (3D) transesophageal echocardiographic (TEE) measurements to severely underestimate multidetector row computed tomographic (MDCT) measurements for the assessment of aortic annulus before transcatheter aortic valve replacement. This study compares annulus measurements from 3D-TEE using off-label use of commercially available software with MDCT measurements and assesses their ability to predict paravalvular regurgitation. Methods and Results—One hundred patients with severe, symptomatic aortic stenosis who had both contrast MDCT and 3D-TEE for annulus assessment before balloon-expandable transcatheter aortic valve replacement were analyzed. Annulus area, perimeter, and orthogonal maximum and minimum diameters were measured. Receiver operating characteristic analysis was performed with mild or greater paravalvular regurgitation as the classification variable. Three-dimensional TEE and MDCT cross-sectional perimeter and area measurements were strongly correlated (r=0.93–0.94; P<0.0001); however, the small differences (⩽1%) were statistically significant (P=0.0002 and 0.0074, respectively). Discriminatory ability for ≥ mild paravalvular regurgitation was good for both MDCT (area under the curve for perimeter and area cover index=0.715 and 0.709, respectively) and 3D-TEE (area under the curve for perimeter and area cover index=0.709 and 0.694, respectively). Differences in receiver operating characteristic analysis between MDCT and 3D-TEE perimeter and area cover indexes were not statistically significant (P=0.15 and 0.35, respectively). Conclusions—Annulus measurements using a new method for analyzing 3D-TEE images closely approximate those of MDCT. Annulus measurements from both modalities predict mild or greater paravalvular regurgitation with equivalent accuracy.

Clinical implications of new-onset left bundle branch block after transcatheter aortic valve replacement: analysis of the PARTNER experience

AIMS Cardiac conduction disturbances, including a left bundle branch block (LBBB), occur frequently following transcatheter aortic valve replacement (TAVR) and may be associated with adverse clinical events. This analysis examines the incidence and implications of new onset, persistent LBBB in patients undergoing TAVR with a balloon-expandable valve. METHODS AND RESULTS Patients undergoing TAVR in the Placement of Aortic Transcatheter Valves (PARTNER) trial and continued access registries with baseline and discharge/7-day electrocardiograms were included. Prior permanent pacemaker implantation (PPI) and baseline intraventricular conduction abnormalities were exclusion criteria. Predictors of new LBBB were identified and outcomes compared between patients with and without new LBBB. New LBBB occurred in 121 of 1151 (10.5%) patients and persisted in more than half at 6 months to 1 year. The only predictor of new LBBB was prior coronary artery bypass grafting. New LBBB was not associated with significant differences in 1-year mortality, cardiovascular mortality, repeat hospitalization, stroke, or myocardial infarction. However, it was associated with increased PPI during hospitalization (8.3 vs 2.8%, P = 0.005) and from discharge to 1 year (4.7 vs. 1.5%, P = 0.01). The ejection fraction failed to improve after TAVR in patients with new LBBB and remained lower at 6 months to 1 year (52.8 vs. 58.1%, P < 0.001). CONCLUSION Persistent, new-onset LBBB occurred in 10.5% of patients without intraventricular baseline conduction who underwent TAVR in the PARTNER experience. New LBBB was not associated with death, repeat hospitalization, stroke, or myocardial infarction at 1 year, but was associated with a higher rate of PPI and failure of left ventricular ejection fraction to improve.

Quantity and location of aortic valve complex calcification predicts severity and location of paravalvular regurgitation and frequency of post-dilation after balloon-expandable transcatheter aortic valve replacement.

OBJECTIVES This study sought to determine the impact of quantity and location of aortic valve calcification (AVC) on paravalvular regurgitation (PVR) and rates of post-dilation (PD) immediately after transcatheter aortic valve replacement (TAVR). BACKGROUND The impact of AVC in different locations within the aortic valve complex is incompletely understood. METHODS This study analyzed 150 patients with severe, symptomatic aortic stenosis who underwent TAVR. Total AVC volume scores were calculated from contrast-enhanced multidetector row computed tomography imaging. AVC was divided by leaflet sector and region (Leaflet, Annulus, left ventricular outflow tract [LVOT]), and a combination of LVOT and Annulus (AnnulusLVOT). Asymmetry was assessed. Receiver-operating characteristic analysis was performed with greater than or equal to mild PVR and PD as classification variables. Logistic regression was performed. RESULTS Quantity of and asymmetry of AVC for all regions of the aortic valve complex predicted greater than or equal to mild PVR by receiver-operating characteristic analysis (area under the curve = 0.635 to 0.689), except Leaflet asymmetry. Receiver-operating characteristic analysis for PD was significant for quantity and asymmetry of AVC in all regions, with higher area under the curve values than for PVR (area under the curve = 0.648 to 0.741). On multivariable analysis, Leaflet and AnnulusLVOT calcification were independent predictors of both PVR and PD regardless of multidetector row computed tomography area cover index. CONCLUSIONS Quantity and asymmetry of AVC in all regions of the aortic valve complex predict greater than or equal to mild PVR and performance of PD, with the exception of Leaflet asymmetry. Quantity of AnnulusLVOT and Leaflet calcification independently predict PVR and PD when taking into account multidetector row computed tomography area cover index.

Detection and Imaging of Cardiac Allograft Vasculopathy

Cardiac allograft vasculopathy (CAV) is an important cause of morbidity and mortality among cardiac transplant recipients. CAV occurs in approximately 30% of patients by 5 years and 50% by 10 years, and is a major cause of graft loss and death. Early detection of CAV is important because it may allow alterations in medical therapy before progression to the stage that revascularization is required. This has led to routine screening for CAV in transplant recipients, traditionally by invasive coronary angiography (ICA). Recent advances in imaging technology, specifically intravascular ultrasound, now also permit detection of subangiographic CAV. Noninvasive stress testing and multislice coronary computed tomography angiography have been investigated as noninvasive alternatives to routine ICA. However, currently available noninvasive tests remain limited with respect to their sensitivity and specificity for CAV. Given the multiple available diagnostic modalities, no consensus definition for the classification of CAV has been widely accepted, although new guidelines that rely heavily on ICA have recently been published by the International Society of Heart and Lung Transplantation. This review summarizes imaging modalities that are utilized in the diagnosis and surveillance of CAV and explores newer imaging techniques that may play a future role.

Chronic pacing and adverse outcomes after transcatheter aortic valve implantation

Objective Many patients undergoing transcatheter aortic valve implantation (TAVI) have a pre-existing, permanent pacemaker (PPM) or receive one as a consequence of the procedure. We hypothesised that chronic pacing may have adverse effects on TAVI outcomes. Methods and results Four groups of patients undergoing TAVI in the Placement of Aortic Transcatheter Valves (PARTNER) trial and registries were compared: prior PPM (n=586), new PPM (n=173), no PPM (n=1612), and left bundle branch block (LBBB)/no PPM (n=160). At 1 year, prior PPM, new PPM and LBBB/no PPM had higher all-cause mortality than no PPM (27.4%, 26.3%, 27.7% and 20.0%, p<0.05), and prior PPM or new PPM had higher rehospitalisation or mortality/rehospitalisation (p<0.04). By Cox regression analysis, new PPM (HR 1.38, 1.00 to 1.89, p=0.05) and prior PPM (HR 1.31, 1.08 to 1.60, p=0.006) were independently associated with 1-year mortality. Surviving prior PPM, new PPM and LBBB/no PPM patients had lower LVEF at 1 year relative to no PPM (50.5%, 55.4%, 48.9% and 57.6%, p<0.01). Prior PPM had worsened recovery of LVEF after TAVI (Δ=10.0 prior vs 19.7% no PPM for baseline LVEF <35%, p<0.0001; Δ=4.1 prior vs 7.4% no PPM for baseline LVEF 35–50%, p=0.006). Paced ECGs displayed a high prevalence of RV pacing (>88%). Conclusions In the PARTNER trial, prior PPM, along with new PPM and chronic LBBB patients, had worsened clinical and echocardiographic outcomes relative to no PPM patients, and the presence of a PPM was independently associated with 1-year mortality. Ventricular dyssynchrony due to chronic RV pacing may be mechanistically responsible for these findings. Trial registration number (ClinicalTrials.gov NCT00530894).

Aortic stenosis and coronary artery disease: What do we know? What don't we know? A comprehensive review of the literature with proposed treatment algorithms

Aortic valve stenosis is the most common form of valvular heart disease in the elderly population and occurs frequently in conjunction with coronary artery disease. The standard treatment option for patients with these two conditions has been surgical aortic valve replacement and coronary artery bypass grafting. The arrival of transcatheter aortic valve replacement has considerably shifted the treatment paradigms. Nevertheless, a lot of questions remain unanswered regarding the management of coronary artery disease in the setting of the transcatheter options for severe aortic stenosis. This article includes a comprehensive review of the literature and seeks to describe the actual knowledge on the topic of aortic stenosis and concomitant coronary artery disease.

Rationale and design of the Transcatheter Aortic Valve Replacement to UNload the Left ventricle in patients with ADvanced heart failure (TAVR UNLOAD) trial

BACKGROUND Coexistence of moderate aortic stenosis (AS) in patients with heart failure (HF) with reduced ejection fraction is not uncommon. Moderate AS increases afterload, whereas pharmacologic reduction of afterload is a pillar of contemporary HF management. HYPOTHESIS Unloading the left ventricle by reducing the transaortic gradient with transfemoral transcatheter aortic valve replacement (TAVR) may improve clinical outcomes in patients with moderate AS and HF with reduced ejection fraction. STUDY DESIGN The TAVR UNLOAD (NCT02661451) is an international, multicenter, randomized, open-label, clinical trial comparing the efficacy and safety of TAVR with the Edwards SAPIEN 3 Transcatheter Heart Valve in addition to optimal heart failure therapy (OHFT) vs OHFT alone in patients with moderate AS (defined by a mean transaortic gradient ≥20 mm Hg and <40 mm Hg, and an aortic valve area >1.0 cm2 and ≤1.5 cm2 at rest or after dobutamine stress echocardiography) and reduced ejection fraction. A total of 600 patients will be randomized in a 1:1 fashion. Clinical follow-up is scheduled at 1, 6, and 12 months, and 2 years after randomization. The primary end point is the hierarchical occurrence of all-cause death, disabling stroke, hospitalizations related to HF, symptomatic aortic valve disease or nondisabling stroke, and the change in the Kansas City Cardiomyopathy Questionnaire at 1 year. Secondary end points capture effects on clinical outcome, biomarkers, echocardiographic parameters, and quality of life. SUMMARY The TAVR UNLOAD trial aims to test the hypothesis that TAVR on top of OHFT improves clinical outcomes in patients with moderate AS and HF with reduced ejection fraction.

Optical Coherence Tomographic Evaluation of Transplant Coronary Artery Vasculopathy With Correlation to Cellular Rejection

Background—Cardiac allograft vasculopathy is an accelerated fibroproliferative process that affects the coronary arteries of transplanted hearts. Intracoronary imaging with optical coherence tomography enables detection of subangiographic cardiac allograft vasculopathy. Methods and Results—At the time of routine surveillance coronary angiography, 48 consecutive heart transplant recipients underwent optical coherence tomographic imaging of 1 coronary artery. Imaging findings were compared per rejection history that was graded according to the International Society of Heart and Lung Transplantation classification as none/mild (International Society of Heart and Lung Transplantation 0, 1A/1B, or 2) or high-grade rejection (≥3A). Compared with the none/mild rejection group (37 patients) using Mann–Whitney U test, patients in the high-grade rejection group (11 patients) had a thicker intima in all coronary segments (distal: 0.22 mm [0.09–0.41] versus 0.09 mm [0.06–0.17], P=0.02; middle: 0.35 mm [0.00–0.45] versus 0.14 mm [0.08–0.24], P=0.002; and proximal: 0.34 mm [0.21–0.44] versus 0.15 mm [0.11–0.21], P=0.005) and a higher prevalence of foamy macrophages (distal: 55% versus 9%, P=0.003; middle: 55% versus 22%, P=0.004; and proximal: 44% versus 13%, P=0.05) using &khgr;2 statistics. Side branches in the high-grade rejection group had smaller lumen diameters and a higher prevalence of intimal thickening (54% versus 36%; P=0.01). Intimal microvessels were also more prevalent in the high-grade rejection group versus the none/mild rejection group (46% versus 11%; P=0.02). Conclusions—Coronary optical coherence tomographic evaluation revealed that patients with a history of high-grade cellular rejection, compared with those with none/mild rejection, had more coronary artery intimal thickening with macrophage infiltration, involving all coronary segments and side branches. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01403142.

Transcatheter Valve Implantation in Failed Surgically Inserted Bioprosthesis: Review and Practical Guide to Echocardiographic Imaging in Valve-in-Valve Procedures.

An increased use of bioprosthetic heart valves has stimulated an interest in possible transcatheter options for bioprosthetic valve failure given the high operative risk. The encouraging results of transcatheter aortic valve implantation in high-risk surgical candidates with native disease have led to the development of the transcatheter valve-in-valve (VIV) procedures for failed bioprostheses. VIV procedures are unique in many ways, and there is an increased need for multimodality imaging in a team-based approach. The echocardiographic approach to VIV procedures has not previously been described. In this review, we summarize key echocardiographic requirements for optimal patient selection, procedural guidance, and immediate post-procedural assessment for VIV procedures.