Michael Mok

Transcatheter aortic valve replacement with the SAPIEN 3: a new balloon-expandable transcatheter heart valve.

OBJECTIVES The aim of this study was to demonstrate the first-in-human feasibility and short-term clinical outcomes with a new balloon-expandable transcatheter heart valve (THV). BACKGROUND The SAPIEN 3 (S3) THV incorporates a paravalvular sealing system, an active 3-dimensional coaxial positioning catheter, and is compatible with a 14-F expandable sheath. METHODS The S3 THV was implanted in 15 patients with symptomatic severe aortic stenosis via femoral arterial access. Multidetector computed tomography before and after valve implantation allowed assessment of a novel annular area sizing algorithm. Clinical and echocardiographic data were obtained at baseline, discharge, and 30 days. RESULTS All 15 device implants were successful. Multidetector computed tomography estimated an aortic annular area of 4.9 ± 0.4 cm(2), predicting 9.7 ± 6.9% THV oversizing. Post-transcatheter aortic valve replacement multidetector computed tomography showed consistently symmetrical and circular THVs. Aortic valve area increased from 0.7 ± 0.2 cm(2) to 1.5 ± 0.2 cm(2) (p < 0.001), and mean transaortic gradient decreased from 42.2 ± 10.3 mm Hg to 11.9 ± 5.3 mm Hg (p < 0.001). No patient had more than mild paravalvular aortic regurgitation. Hospital discharge occurred at a median of 3 (range 2 to 12) hospital days. At 30 days there were no deaths, strokes, vascular complications, bleeds, or transfusions, although 1 patient (6.7%) required a new pacemaker. All patients were in New York Heart Association functional class I or II. CONCLUSIONS The S3 THV and delivery system might facilitate fully percutaneous implantation in a broader range of patients with the potential for more accurate positioning and less paravalvular regurgitation.

Predictive factors and long-term clinical consequences of persistent left bundle branch block following transcatheter aortic valve implantation with a balloon-expandable valve

OBJECTIVES This study evaluated the predictive factors and prognostic value of new-onset persistent left bundle branch block (LBBB) in patients undergoing transcatheter aortic valve implantation (TAVI) with a balloon-expandable valve. BACKGROUND The predictors of persistent (vs. transient or absent) LBBB after TAVI with a balloon-expandable valve and its clinical consequences are unknown. METHODS A total of 202 consecutive patients with no baseline ventricular conduction disturbances or previous permanent pacemaker implantation (PPI) who underwent TAVI with a balloon-expandable valve were included. Patients were on continuous electrocardiographic (ECG) monitoring during hospitalization and 12-lead ECG was performed daily until hospital discharge. No patient was lost at a median follow-up of 12 (range: 6 to 24) months, and ECG tracing was available in 97% of patients. The criteria for PPI were limited to the occurrence of high-degree atrioventricular block (AVB) or severe symptomatic bradycardia. RESULTS New-onset LBBB was observed in 61 patients (30.2%) after TAVI, and had resolved in 37.7% and 57.3% at hospital discharge and 6- to 12-month follow-up, respectively. Baseline QRS duration (p = 0.037) and ventricular depth of the prosthesis (p = 0.017) were independent predictors of persistent LBBB. Persistent LBBB at hospital discharge was associated with a decrease in left ventricular ejection fraction (p = 0.001) and poorer functional status (p = 0.034) at 1-year follow-up. Patients with persistent LBBB and no PPI at hospital discharge had a higher incidence of syncope (16.0% vs. 0.7%; p = 0.001) and complete AVB requiring PPI (20.0% vs. 0.7%; p < 0.001), but not of global mortality or cardiac mortality during the follow-up period (all, p > 0.20). New-onset LBBB was the only factor associated with PPI following TAVI (p < 0.001). CONCLUSIONS Up to 30% of patients with no prior conduction disturbances developed new LBBB following TAVI with a balloon-expandable valve, although it was transient in more than one third. Longer baseline QRS duration and a more ventricular positioning of the prosthesis were associated with a higher rate of persistent LBBB, which in turn determined higher risks for complete AVB and PPI, but not mortality, at 1-year follow-up.

Predictive factors, efficacy, and safety of balloon post-dilation after transcatheter aortic valve implantation with a balloon-expandable valve

OBJECTIVES This study sought to evaluate the predictive factors, effects, and safety of balloon post-dilation (BPD) for the treatment of significant paravalvular aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI). BACKGROUND Very few data exist on BPD after TAVI with a balloon-expandable valve. METHODS A total of 211 patients who underwent TAVI with a balloon-expandable valve were included. BPD was performed after TAVI if paravalvular AR ≥ 2 was identified by transesophageal echocardiography. Clinical events and echocardiographic data were prospectively recorded, and median follow-up was 12 (6 to 24) months. RESULTS BPD was performed in 59 patients (28%), leading to a reduction in at least 1 degree of AR in 71% of patients, with residual AR <2 in 54% of the patients. The predictors of the need for BPD were the degree of valve calcification and transfemoral approach, with valve calcification volume >2,200 and >3,800 mm(3) best determining the need for and a poor response to BPD, respectively. Patients who underwent BPD had a higher incidence of cerebrovascular events at 30 days (11.9% vs. 2.0%, p = 0.006), with most (83%) events within the 24 h after the procedure occurring in patients who had BPD. No significant changes in valve area or AR degree were observed at follow-up in BPD and no-BPD groups. CONCLUSIONS BPD was needed in about one-fourth of the patients undergoing TAVI with a balloon-expandable valve and was successful in about one-half of them. A higher degree of valve calcification and transfemoral approach predicted the need for BPD. BPD was not associated with any deleterious effect on valve function at mid-term follow-up, but a higher rate of cerebrovascular events was observed in patients who had BPD.

Coronary obstruction following transcatheter aortic valve implantation: a systematic review.

OBJECTIVES This study sought to evaluate, through a systematic review of the published data, the main baseline characteristics, management, and clinical outcomes of patients suffering coronary obstruction as a complication of transcatheter aortic valve implantation (TAVI). BACKGROUND Very few data exist on coronary obstruction after TAVI. METHODS Studies published between 2002 and 2012, with regard to coronary obstruction as a complication of TAVI, were identified with a systematic electronic search. Only the studies reporting data on the main baseline and procedural characteristics, management of the complication, and clinical outcomes were analyzed. RESULTS A total of 18 publications describing 24 patients were identified. Most (83%) patients were women, with a mean age of 83 ± 7 years and a mean logistic European System for Cardiac Operative Risk Evaluation score of 25.1 ± 12.0%. Mean left coronary artery (LCA) ostium height and aortic root width were 10.3 ± 1.6 mm and 27.8 ± 2.8 mm, respectively. Most patients (88%) had received a balloon-expandable valve, and coronary obstruction occurred more frequently in the LCA (88%). Percutaneous coronary intervention was attempted in 23 cases (95.8%) and was successful in all but 2 patients (91.3%). At 30-day follow-up, there were no cases of stent thrombosis or repeat revascularization, and the mortality rate was 8.3%. CONCLUSIONS Reported cases of coronary obstruction after TAVI occurred more frequently in women, in patients receiving a balloon-expandable valve, and the LCA was the most commonly involved artery. Percutaneous coronary intervention was a feasible and successful treatment in most cases. Continuous efforts should be made to identify the factors associated with this life-threatening complication to implement the appropriate measures for its prevention.

Prevention of Dabigatran-Related Gastrointestinal Bleeding With Gastroprotective Agents: A Population-Based Study

BACKGROUND & AIMS Use of dabigatran, an inhibitor of thrombin, increases the risk of gastrointestinal bleeding (GIB). However, it is not clear whether gastroprotective agents (GPAs) prevent GIB in dabigatran users. We investigated the risk of GIB and the role of gastroprotective agents (including proton pump inhibitors and histamine type-2-receptor antagonists) in patients using dabigatran. METHODS We performed a retrospective cohort study using a population-wide database managed by the Hong Kong Hospital Authority. Patients newly prescribed dabigatran from 2010 through 2013 were included in the analysis. Poisson regression was used to assess the risk of GIB in dabigatran users by incidence rate ratio (IRR), adjusted for patient characteristics, comorbidities, and concurrent medications. RESULTS Among the 5041 patients newly prescribed dabigatran, 124 (2.5%) developed GIB during follow-up evaluation (4.2/100 patient-years). The risk of GIB in this population increased among patients 75 years and older (IRR, 2.47; 95% confidence interval [CI], 1.66-3.68), patients with a history of peptic ulcers or GIB (IRR, 2.31; 95% CI, 1.54-3.46), and patients who used aspirin (IRR, 1.52; 95% CI, 1.03-2.24). Concomitant use of gastroprotective agents was associated with a reduced risk of GIB (IRR, 0.52; 95% CI, 0.35-0.77). Subcategory analysis showed that use of proton pump inhibitors (IRR, 0.53; 95% CI, 0.31-0.91) or histamine type-2-receptor antagonists (IRR, 0.61; 95% CI, 0.40-0.94) were associated with a lower risk of GIB. Further analysis showed that the risk reduction by gastroprotective agents was significant for only upper GIB (IRR, 0.29; 95% CI, 0.15-0.54), and only for patients with a prior history of peptic ulcers or GIB (IRR, 0.14; 95% CI, 0.06-0.30). CONCLUSIONS In the Hong Kong population, use of gastroprotective agents was associated with a reduced risk of GIB in patients taking dabigatran. The association was stronger for upper GIB than lower GIB, and in patients with a prior history of peptic ulcers or GIB.

Chronic Obstructive Pulmonary Disease in Patients Undergoing Transcatheter Aortic Valve Implantation: Insights on Clinical Outcomes, Prognostic Markers, and Functional Status Changes

OBJECTIVES This study sought to determine the effects of chronic obstructive pulmonary disease (COPD) on clinical outcomes in patients undergoing transcatheter aortic valve implantation (TAVI) and to determine the factors associated with worse outcomes in COPD patients. BACKGROUND No data exist on the factors determining poorer outcomes in COPD patients undergoing TAVI. METHODS A total of 319 consecutive patients (29.5% with COPD) who underwent TAVI were studied. Functional status was evaluated by New York Heart Association (NYHA) functional class, Duke Activity Status Index, and the 6-min walk test (6MWT) at baseline and at 6 to 12 months. The TAVI treatment was considered futile if the patient either died or did not improve in NYHA functional class at 6-month follow-up. RESULTS Survival rates at 1 year were 70.6% in COPD patients and 84.5% in patients without COPD (p = 0.008). COPD was an independent predictor of cumulative mortality after TAVI (hazard ratio: 1.84; 95% confidence interval: 1.08 to 3.13; p = 0.026). Improvement in functional status was observed after TAVI (p < 0.001 for NYHA functional class, Duke Activity Status Index, and 6MWT), but COPD patients exhibited less (p = 0.036) improvement in NYHA functional class. Among COPD patients, a shorter 6MWT distance predicted cumulative mortality (p = 0.013), whereas poorer baseline spirometry results (FEV1 [forced expiratory volume in the first second of expiration]) determined a higher rate of periprocedural pulmonary complications (p = 0.040). The TAVI treatment was futile in 40 COPD patients (42.5%) and a baseline 6MWT distance <170 m best determined the lack of benefit after TAVI (p = 0.002). CONCLUSIONS COPD was associated with a higher rate of mortality at mid-term follow-up. Among COPD patients, a higher degree of airway obstruction and a lower exercise capacity determined a higher risk of pulmonary complications and mortality, respectively. TAVI was futile in more than one-third of the COPD patients, and a shorter distance walked at the 6MWT predicted the lack of benefit after TAVI. These results may help to improve the clinical decision-making process in this challenging group of patients.

Comparison of hemodynamic performance of self-expandable CoreValve versus balloon-expandable Edwards SAPIEN aortic valves inserted by catheter for aortic stenosis.

Transcatheter aortic valve implantation with the self-expandable CoreValve (CV) and the balloon-expandable Edwards SAPIEN (ES) bioprostheses has been widely used for the treatment of severe aortic stenosis. However, a direct comparison of the hemodynamic results associated with these 2 prostheses is lacking. The aim of the present study was to compare the hemodynamic performance of both bioprostheses. A total of 41 patients who underwent transcatheter aortic valve implantation with the CV prosthesis were matched 1:1 for prosthesis size (26 mm), aortic annulus size, left ventricular ejection fraction, body surface area, and body mass index with patients who underwent transcatheter aortic valve implantation with the ES prosthesis. Doppler-echocardiographic data were prospectively collected before the intervention and at hospital discharge, and all examinations were sent to, and analyzed in, a central echocardiography core laboratory. The mean transprosthetic residual gradient was lower (p = 0.024) in the CV group (7.9 ± 3.1 mm Hg) than in the ES group (9.7 ± 3.8 mm Hg). The effective orifice area tended to be greater in the CV group (1.58 ± 0.31 cm(2) vs 1.49 ± 0.24 cm(2), p = 0.10). The incidence of severe prosthesis-patient mismatch was, however, similar between the 2 groups (effective orifice area indexed to the body surface area ≤0.65 cm(2)/m(2); CV 9.8%, ES 9.8%, p = 1.0). The incidence of paravalvular aortic regurgitation was greater with the CV (grade 1 or more in 85.4%, grade 2 or more in 39%) than with the ES (grade 1 or more in 58.5%, grade 2 or more in 22%; p = 0.001). The number and extent of paravalvular leaks were greater in the CV group (p <0.01 for both comparisons). In conclusion, transcatheter aortic valve implantation with the CV prosthesis was associated with a lower residual gradient but a greater rate of paravalvular aortic regurgitation compared to the ES prosthesis. The potential clinical consequences of the differences in hemodynamic performance between these transcatheter heart valves needs to be addressed in future studies.

Effect of thoracic epidural analgesia on clinical outcomes following transapical transcatheter aortic valve implantation

Objective To determine the impact of perioperative thoracic epidural analgesia (TEA) on acute and late outcomes following transapical transcatheter aortic valve implantation (TA-TAVI). Patients and intervention A total of 135 consecutive patients who underwent TA-TAVI were included. All patients received catheter-based pain control, either via TEA (TEA group, n=74) or intercostal local analgesia with a catheter placed at the surgical incision site (non-TEA group, n=61), depending on the preference of the anaesthesiologist responsible for the case. Main outcome measures Pain level during early postoperative period (verbal rating scale from 1 to 10), 30-day/in-hospital complications and mortality, and 1-year mortality. Results There were no differences in baseline or procedural characteristics between groups except for a lower left ventricular ejection fraction in the TEA group. The maximal pain score related to thoracotomy in the postoperative period was higher in the non-TEA group as compared with the TEA group (4 (IQR: 3–5)) vs 2 (IQR: 1–3), p<0.001). Non-TEA was associated with a higher rate of pulmonary complications (p<0.05 for nosocomial pneumonia, reintubation and tracheostomy). The 30-day/in-hospital mortality rate was higher in the non-TEA group (22.9% vs 2.7% in the TEA group, p<0.001). At 1-year follow-up, overall mortality remained higher in the non-TEA group (31.1%) compared with the TEA group (10.8%), p=0.005. Similar periprocedural and late results were obtained in a propensity score-matched analysis that included 100 matched patients. In the multivariable analysis, STS score (p=0.027) and absence of TEA (p=0.039) were independent predictors of increased cumulative late mortality. Conclusions TEA provided superior analgesia following TA-TAVI, and was associated with a dramatic reduction in periprocedural respiratory complications, and both, short- and long-term mortality. These results highlight the importance of obtaining optimal analgesia following TA-TAVI to improve the results associated with this procedure.

Working Toward a Frailty Index in Transcatheter Aortic Valve Replacement: A Major Move Away From the “Eyeball Test”

Objective/setting To provide a population-based analysis of childhood road traffic injuries (RTI) in two communities of the greater Accra region of Ghana, with the goal of establishing an RTI incidence baseline in these communities and to identify RTI characteristics in order to model a targeted injury prevention programme. Study design Geographical cluster sampling was performed in two separate communities with household surveys administered in person to determine a denominator. The guardian responsible for any household members below the age of 15 years involved in an RTI within the previous 12 months received an in-depth questionnaire. Demographics, incident characteristics, medical attention, injuries and disability days were noted. These are described and compared with injury severity and age-specific tendencies. Results 5128 children were interviewed in 60 clusters. Of them, 172 were involved in an RTI within the previous 12 months. This resulted in a rate of 34 RTI/1000 person-years, and 43 RTI/1000 person-years in the 5–14-year-old age group. RTI involving a mini-bus taxi, as a pedestrian, correlated with a disability of greater than 30 days, as did fractures. 35.8% of injuries occurred at sunset. Most RTI occurred on a highway and involved the lower extremities. There were two deaths resulting in an incidence of 39.0/100 000 person-years. Conclusion Childhood RTI in this urban west African setting are a major source of disability. Specific injury circumstances are reviewed in detail. This study provides baseline incidence data that may be used to measure injury prevention efforts and to validate secondary data sources.

Prognostic Value of Fat Mass and Skeletal Muscle Mass Determined by Computed Tomography in Patients Who Underwent Transcatheter Aortic Valve Implantation

Body composition (fat mass [FM] and skeletal muscle mass [SMM]) predicts clinical outcomes. In particular, loss of SMM (sarcopenia) is associated with frailty and mortality. There are no data on the prevalence and impact of FM and SMM in patients undergoing transcatheter aortic valve implantation (TAVI). The objective of this study is to determine body composition from pre-TAVI computed tomography (CT) and evaluate its association with clinical outcomes in patients who underwent TAVI. A total of 460 patients (mean age 81 ± 8 years, men: 51%) were included. Pre-TAVI CTs of the aorto-ilio-femoral axis were analyzed for FM and SMM cross-sectional area at the level of the third lumbar vertebrae (L3). Regression equations correlating cross-sectional area at L3 to total body FM and SMM were used to determine prevalence of sarcopenia, obesity, and sarcopenic obesity in patients (64%, 65%, and 46%, respectively). Most TAVI procedures were performed through a transfemoral approach (59%) using a balloon-expandable valve (94%). The 30-day and mid-term (median 12 months [interquartile range 6 to 27]) mortality rates were 6.1% and 29.6%, respectively. FM had no association with clinical outcomes, but sarcopenia predicted cumulative mortality (hazard ratio 1.55, 95% confidence interval 1.02 to 2.36, p = 0.04). In conclusion, body composition analysis from pre-TAVI CT is feasible. Sarcopenia, obesity, and sarcopenic obesity are prevalent in the TAVI population, with sarcopenia predictive of cumulative mortality.