Rationale and Design of the Randomized Bayesian Multicenter COME-TAVI Trial in Patients With a New Onset Left Bundle Branch Block.

Patients with new-onset left bundle branch block (LBBB) after transcatheter aortic valve implantation (TAVI) are at risk of developing delayed high-degree atrioventricular block. Management of new-onset LBBB post-TAVI remains controversial. In the Comparison of a Clinical Monitoring Strategy Versus Electrophysiology-Guided Algorithmic Approach in Patients With a New LBBB After TAVI (COME-TAVI) trial, consenting patients with new-onset LBBB that persists on day 2 after TAVI, meeting exclusion/inclusion criteria, are randomized to an electrophysiological study (EPS)-guided approach or 30-day electrocardiographic monitoring. In the EPS-guided approach, patients with a His to ventricle (HV) interval ≥ 65 ms undergo permanent pacemaker implantation. Patients randomized to noninvasive monitoring receive a wearable continuous electrocardiographic recording and transmitting device for 30 days. Follow-up will be performed at 3, 6, and 12 months. The primary endpoint is a composite outcome designed to capture net clinical benefit. The endpoint incorporates major consequences of both strategies in patients with new-onset LBBB after TAVI, as follows: (i) sudden cardiac death; (ii) syncope; (iii) atrioventricular conduction disorder requiring a pacemaker (for a class I or IIa indication); and (iv) complications related to the pacemaker or EPS. The trial incorporates a Bayesian design with a noninformative prior, outcome-adaptive randomization (initially 1:1), and 2 prespecified interim analyses once 25% and 50% of the anticipated number of primary endpoints are reached. The trial is event-driven, with an anticipated upper limit of 452 patients required to reach 77 primary outcome events over 12 months of follow-up. In summary, the aim of this Bayesian multicentre randomized trial is to compare 2 management strategies in patients with new-onset LBBB post-TAVI-an EPS-guided approach vs noninvasive 30-day monitoring. Trial registration number: NCT03303612.

Les patients chez qui un bloc de branche gauche (BBG) est récemment apparu à la suite de l'implantation valvulaire aortique par cathéter (IVAC) présentent un risque de bloc auriculoventriculaire de haut degré tardif. La prise en charge d'un BBG récemment apparu après une IVAC demeure controversée. Dans le cadre de l'essai COME-TAVI (Comparison of a ClinicalMonitoring Strategy VersusElectrophysiology-Guided Algorithmic Approach in Patients With a New LBBB AfterTAVI, ou comparaison d'une stratégie de surveillance clinique, par rapport à une approche guidée par étude électrophysiologique et fondée sur un algorithme, chez des patients présentant un BBG d'apparition récente à la suite d'une IVAC), des patients qui présentent un BBG d'apparition récente persistant le 2e jour après une IVAC, qui répondent aux critères d'admissibilité et qui ont donné leur consentement sont répartis aléatoirement pour être suivis à l'aide d'une approche guidée par une étude électrophysiologique (EEP) ou faire l'objet d'une surveillance électrocardiographique d'une durée de 30 jours. Un stimulateur cardiaque est implanté chez les patients du groupe de l'EEP dont l'intervalle HV (temps de conduction dans le tronc du faisceau de His jusqu'aux ventricules) est ≥ 65 ms. Les patients du groupe de surveillance non invasive reçoivent un dispositif portable d'enregistrement et de transmission continue de données électrocardiographiques pour une période de 30 jours. Le suivi sera réalisé aux 3e, 6e et 12e mois. Le critère d'évaluation principal est un paramètre composite conçu afin de saisir le bienfait clinique net. Il comprend les conséquences majeures des deux stratégies chez les patients présentant un BBG d'apparition récente après une IVAC, comme suit : (i) mort subite d'origine cardiaque; (ii) syncope; (iii) trouble de la conduction auriculoventriculaire nécessitant la pose d'un stimulateur cardiaque (pour une indication de classe I ou IIa); et (iv) complications relatives au stimulateur cardiaque ou à l'EEP. L'essai intègre une conception bayésienne avec une répartition aléatoire (dans un rapport initial de 1:1) antérieure non informative adaptée aux résultats et deux analyses intermédiaires définies au préalable lorsque 25 % et 50 % du nombre anticipé des critères d'évaluation principaux seront atteints. L'essai est axé sur les événements, et la limite supérieure anticipée pour atteindre 77 événements relatifs aux critères d'évaluation principaux sur 12 mois de suivi est de 452 patients. En résumé, l'objectif de cet essai bayésien multicentrique à répartition aléatoire est de comparer deux stratégies de prise en charge de patients présentant un BBG d'apparition récente après une IVAC, soit une approche guidée par une EEP, par rapport à une surveillance non invasive de 30 jours. Trial registration number: NCT03303612.

Novel Humanized Biosimulator to Predict Coronary Obstruction in High-Risk Valve-in-Valve Procedures.

We developed humanized biosimulator to predict the risk of coronary obstruction among high-risk patients undergoing valve-in-valve (ViV) procedures. In this case, based on unchanged instantaneous wave-free ratio values measured during a ViV simulation session, the procedure was performed safely in the patient the day afterward, without coronary artery issues and with good hemodynamic results. (Level of Difficulty: Advanced.).

Growth Differentiation Factor-15 as a Predictor of Functional Capacity, Frailty, and Ventricular Dysfunction in Patients With Aortic Stenosis and Preserved Left Ventricular Ejection Fraction.

In aortic stenosis (AS), left ventricular (LV) remodeling often occurs before symptom onset, and early intervention may be beneficial. Risk stratification remains challenging and identification of biomarkers may be useful. We evaluated the association between growth differentiation factor-15 (GDF-15) and soluble suppression of tumorigenicity 2 (sST2) and known markers of poor prognosis in AS. Baseline plasma GDF-15 and sST2 levels were measured in 70 patients with moderate-severe AS (aortic valve area <1.5 cm2) and preserved LV ejection fraction (>45%). Patients were categorized into "low GDF-15" versus "high GDF-15" and "low sST2" versus "high sST2" groups. Groups were compared for differences in cardiovascular risk factors, 6-minute walk test, 5 m gait speed, cognitive function (Montreal Cognitive Assessment), and echocardiographic parameters. Overall, 44% of patients were deemed asymptomatic by New York Heart Association class, 61% had severe AS (aortic valve area <1 cm2) and all patients had preserved LV ejection fraction. GDF-15 levels were not predictive of AS severity. However, high GDF-15 (>1,050 pg/ml) was associated with LV dysfunction as shown by lower indexed stroke volume (p <0.01), worse LV global longitudinal strain (p = 0.04), greater mean E/e' (p = 0.02) and indexed left atrial volume (p <0.01). It was also associated with decreased functional capacity with shorter 6-minute walk test (p = 0.01) and slower 5 m gait speed (p = 0.02). Associations between sST2 levels and markers of poor prognosis were less compelling. In this study of patients with moderate to severe AS, elevated GDF-15 levels are associated with impaired functional capacity, poorer performance on fragility testing, and LV dysfunction. In conclusion, GDF-15 may integrate these markers of adverse outcomes into a single biomarker of poor prognosis.

Bioprosthetic Valve Fracture After TAVR Complicated by Balloon Rupture: Bail-Out TAVR in TAVR in SAVR.

Transcatheter aortic valve replacement in surgical aortic valve is a safe and effective procedure to treat patients with failed bioprosthetic surgical valves at high risk for reoperation. Performing bioprosthetic valve fracture has been shown to improve postprocedural hemodynamics of TAVR in surgical aortic valve replacement. However, specific complications related to valve fracture are becoming more common. (Level of Difficulty: Advanced.).

The Evolution of Transcatheter Therapies for Mitral Valve Disease: From Mitral Valvuloplasty to Transcatheter Mitral Valve Replacement.

The prevalence of mitral valve disease has evolved over the past 5 decades from primarily a disease of rheumatic origin to a disease affecting the aging population that encompasses a range of phenotypes from rheumatic mitral stenosis, degenerative mitral regurgitation, and degenerative mitral valve calcification to secondary mitral regurgitation. A reflection on the history of therapy for mitral valve disease is an expedition that follows the birth and development of structural heart intervention from the first percutaneous balloon mitral valvuloplasty to innovative technologies for transcatheter mitral valve repair and replacement. This review will lead you along this journey, pause to acknowledge the feats accomplished, and reflect on the road that lies ahead.

Initial clinical experience with VersaCross transseptal system for transcatheter mitral valve repair.

OBJECTIVES: The aim of this study is to describe the initial experience with versacross transseptal (TS) system for transseptal puncture for the transcatheter mitral valve repair using the MitraClip device. BACKGROUND: Transeptal puncture is a key step in transcatheter mitral valve repair (MVR) and the use of the VersaCross system comprised of a sheath, a dilator and a radiofrequency wire has not been previously described. METHODS: Prospective single center study of consecutive patients undergoing transcatheter mitral valve repair with the MitraClip device were included. Targeted TS puncture was performed under transesophageal echocardiographic (TEE) guidance. Baseline demographics, procedural characteristics, and major adverse procedural events were collected. RESULTS: Twenty-five consecutive patients underwent transseptal puncture using the VersaCross TS system. Transseptal puncture was successful in 100% of patients. The mean time for TS puncture was 3 3 ± 1.6 min with no major adverse procedural events. The mean time from insertion of the VersaCross system to insertion of the MitraClip guide catheter was 3.8 ± 3.0 minutes. CONCLUSION: The VersaCross TS system was successful in all patients for MitraClip procedure with no adverse procedural events and may be associated with increased procedural efficiency.

Successful implantation of self-expanding valve for a failed stentless prosthesis.

Valve-in-valve transcatheter aortic valve implantation is currently used for failed bioprosthesis. The use of a transcatheter prosthesis in a regurgitant noncalcified root implanted Medtronic Freestyle prosthesis is particularly challenging. We present a successful transaxillary valve-in-valve implantation of a self-expandable transcatheter aortic valve prosthesis in a failed Freestyle bioprothesis implanted eleven years earlier. Tips and tricks are discussed.

Clinical outcomes of bioresorbable vascular scaffold to treat all-comer patients. Are patients with acute coronary syndrome better candidates for bioresorbable vascular scaffold?

BACKGROUND: Scaffold thromboses (ST) and adverse events and have been associated with bioresorbable vascular scaffolds (BVS) at long-term, but their mechanism remains unclear. We sought to evaluate patient and lesion characteristics associated with mid- to long-term outcomes in patients treated with BVS. METHODS: This is an observational single-center, single-arm, retrospective study evaluating the performance of BVS in an all-comer population, including complex lesions (chronic total occlusions, long lesions), small vessels, and acute coronary syndromes (ACS). RESULTS: From May 2013 to June 2015, we included 482 patients (580 lesions) that were treated with BVS implantation including 71.2% treated for ACS in the present analysis. Mean follow-up period was 816.2 ±â€¯242.6 days. The primary endpoint was device oriented cardiac events (DOCE), defined as a composite of target-lesion revascularization (TLR), ST, target vessel myocardial infarction (TVMI) and cardiac death. Using Kaplan-Meier methods, the DOCE and ST rates at 36 months were 9.4% and 2.3%, respectively. No ST occurred between 2 and 3 years and ST occurred after 3 years, in one patient. Using multivariate analysis, ACS was the only significant predictor of lower rates of DOCE (p = 0.04, HR: 0.47, 95% CI: 0.23-0.96). CONCLUSIONS: In this large all-comers real-world cohort, lesions treated with BVS had non-negligible rates of DOCE and ST, in line with previous published randomized trials. The occurrence of very late event was very low after 24 months. ACS patients had lower rates of DOCE.

Cost consequence analysis of use of a balloon expandable vascular access system and standard vascular sheath for transcatheter aortic valve implantation.

BACKGROUND: Vascular complications are an important complication of transcatheter aortic valve implantation and are associated with increased morbidity and mortality as well as cost. The Solopath device is an expandable vascular access system that has previously been shown to be associated with lower rates of vascular complications. This study sought to evaluate the impact of the use of this system on vascular complications and costs in a decision model analysis. METHODS: A cost-consequence analysis was undertaken utilizing event rate data from the PARTNER trials and a published retrospective analysis of the Solopath device. The decision model estimated costs and benefits in a hypothetical cohort of patients with aortic stenosis undergoing TAVI using either a standard sheath or Solopath. The modeled analysis compared the occurrence of vascular complications and mortality at 30 days and 1 year using TreeAge Pro. RESULTS: The decision model demonstrated that use of the Solopath sheath resulted in 36 fewer major vascular complications, three fewer deaths at 30 days, and five fewer deaths at 1 year, resulting in a discounted cost savings of $846 CDN. Results were sensitive to decreasing rates of vascular complications with newer generation devices, however maintained modest cost-savings. CONCLUSIONS: Reduction in vascular complications is an important part of improving care for TAVI patients. The Solopath vascular access device offers an alternative to standard sheaths with a potential reduction in complications and cost-savings.

Clinical outcomes and economic impact of transcatheter mitral leaflet repair in heart failure patients.

BACKGROUND: Mitral regurgitation (MR) is a common valvular heart disorder requiring intervention once it becomes severe. Transcatheter mitral repair with the MitraClip device is a safe and effective therapy for selected patients denied surgery. The authors sought to evaluate the clinical outcomes and economic impact of this therapy compared to medical management in heart-failure patients with symptomatic mitral regurgitation. METHODS AND RESULTS: The study was comprised of two phases; an observational study of patients with heart failure and mitral regurgitation treated with either medical therapy or the MitraClip, and an economic model. Results of the observational study were used to estimate parameters for the decision model, which estimated costs, and benefits in a hypothetical cohort of patients with heart failure and moderate-to-severe mitral regurgitation treated with either standard medical therapy or MitraClip. The cohort of patients treated with the MitraClip was propensity matched to a population of heart failure patients, and their outcomes compared. At a mean follow-up of 22 months, all-cause mortality was 21% in the MitraClip cohort and 42% in the medical management cohort (p = .007). The decision model demonstrated that MitraClip increased life expectancy from 1.87-3.60 years and quality-adjusted life years (QALY) from 1.13-2.76 years. The incremental cost was $52,500 Canadian dollars, corresponding to an incremental cost-effectiveness ratio (ICER) of $32,300.00 per QALY gained. Results were sensitive to the survival benefit. CONCLUSION: In heart failure patients with symptomatic moderate-severe mitral regurgitation, therapy with the MitraClip is associated with superior survival and is cost-effective compared to medical therapy.

Four-year experience with the CoreValve transcatheter heart valve.

AIMS: Our aim was to evaluate the long-term device performance and clinical outcomes of patients with symptomatic, severe aortic valve stenosis (AS) who underwent transcatheter aortic valve implantation (TAVI) with the CoreValve bioprosthesis. METHODS AND RESULTS: The CoreValve CE Pivotal Study was a prospective, multicentre, single-arm TAVI trial using the CoreValve system. Valve performance, patient quality of life (QoL), New York Heart Association (NYHA) class, and mortality at four years were analysed in 126 patients (mean age 82.4 years, 42.9% male, mean logistic EuroSCORE 23.4%) with severe AS. Mean aortic valve gradient decreased from 46.9±16.1 mmHg at baseline to 9.8±4.1 mmHg at discharge and to 7.8±2.7 mmHg at four years. Mean effective orifice area increased from 0.7±0.2 cm2 to 1.8±0.4 cm2 after TAVI and was 1.6±0.5 cm2 at four years. There were no reports of structural valve deterioration or valve migration. There was sustained improvement in QoL and NYHA class in surviving patients. All-cause and cardiac survival was 45.3% and 62.6%, respectively, at four years. CONCLUSIONS: The CoreValve bioprosthesis demonstrates long-term durability, stable haemodynamic function, and no evidence of structural deterioration. Most surviving patients continued to have improved NYHA class and QoL at four years.

Efficacy of a balloon-expandable vascular access system in transfemoral TAVI patients.

BACKGROUND: Vascular complications (VC) are a serious and frequent complication of transfemoral transcatheter aortic valve implantation (TAVI) and result in increased morbidity and mortality. It has been suggested that newly developed vascular sheaths may increase the ability to perform transfemoral TAVI in patients with normal and access-limiting peripheral artery disease (PAD) and reduce vascular complications. AIMS: We sought to assess the safety and efficacy of the 19 French (F) SoloPath balloon-expandable transfemoral vascular access system in patients who underwent transfemoral TAVI at our center between 2011 and 2014. METHODS AND RESULTS: Single-center retrospective study of 90 patients who underwent transfemoral TAVI with the use of the SoloPath sheath. Patients were categorized into two groups according to a sheath to femoral artery ratio (SFAR) of less than or equal to 1.05, or greater than 1.05. Overall, the incidence of major bleeding complications was low, 4.4%. No significant differences were found in technical or procedural success rates (100% in both groups and 100% vs. 91.3; P = 0.09; respectively), total vascular complications (20.8 vs. 21.7; P = 0.92) or total bleeding complications (20.8 vs. 30.4; P = 0.36 between those with SFAR greater or less than 1.05. CONCLUSIONS: The use of the SoloPath balloon-expandable sheath is feasible and safe even in patients with SFAR > 1.05, showing no increased vascular or bleeding complications compared to patients with larger vascular access. © 2016 Wiley Periodicals, Inc.

Impact of left ventricular function on clinical outcomes of functional mitral regurgitation patients undergoing transcatheter mitral valve repair.

OBJECTIVES: To evaluate the impact of baseline left ventricular (LV) function on the clinical outcomes of patients with functional mitral regurgitation (FMR) treated with MitraClip. BACKGROUND: It is unknown whether patients with significant FMR and severe LV dysfunction benefit from MitraClip. METHODS: A cohort of 77 patients with significant FMR undergoing MitraClip procedure between December 2010 and January 2015 was categorized by baseline LV ejection fraction (LVEF) into tertiles: LVEF <27% (n = 27), LVEF 27-37% (n = 25), and LVEF >37% (n = 25). We sought to evaluate the impact of LVEF on all-cause mortality at follow-up. RESULTS: There were no significant differences in baseline comorbidities, medical treatment and MR severity among tertiles of LVEF. Overall procedural success was 94%, with no differences among groups (LVEF <27%: 89%; LVEF 27-37%: 100%; LVEF >37%: 92%; P = 0.25). Median follow-up was 372 days (interquartile range: 128-627 days). MR severity improved in all three groups, as compared to baseline. There were no differences in the prevalence of MR ≤2+ on follow-up (P = 0.40). Mortality was highest in patients with LVEF <27% (41%), as compared with LVEF 27-37% (16%) and LVEF >37% (4%), P = 0.004. Patient who died had a lower baseline LVEF compared to those who survived (24.8 ± 7.7% versus 35.5 ± 13.7%, P < 0.001). An LVEF <27% was an independent predictor of mortality after adjusting for procedural success: hazard ratio 3.4 (95% CI: 1.1 to 10.0; P = 0.030). CONCLUSIONS: MitraClip is effective in FMR patients regardless of the severity of LV dysfunction. However, low baseline LVEF is associated with increased mortality, despite procedural success. © 2016 Wiley Periodicals, Inc.

The Benefits Conferred by Radial Access for Cardiac Catheterization Are Offset by a Paradoxical Increase in the Rate of Vascular Access Site Complications With Femoral Access: The Campeau Radial Paradox.

OBJECTIVES: The purpose of this study was to assess whether the benefits conferred by radial access (RA) at an individual level are offset by a proportionally greater incidence of vascular access site complications (VASC) at a population level when femoral access (FA) is performed. BACKGROUND: The recent widespread adoption of RA for cardiac catheterization has been associated with increased rates of VASCs when FA is attempted. METHODS: Logistic regression was used to calculate the adjusted VASC rate in a contemporary cohort of consecutive patients (2006 to 2008) where both RA and FA were used, and compared it with the adjusted VASC rate observed in a historical control cohort (1996 to 1998) where only FA was used. We calculated the adjusted attributable risk to estimate the proportion of VASC attributable to the introduction of RA in FA patients of the contemporary cohort. RESULTS: A total of 17,059 patients were included. At a population level, the VASC rate was higher in the overall contemporary cohort compared with the historical cohort (adjusted rates: 2.91% vs. 1.98%; odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.17 to 1.89; p = 0.001). In the contemporary cohort, RA patients experienced fewer VASC than FA patients (adjusted rates: 1.44% vs. 4.19%; OR: 0.33, 95% CI: 0.23 to 0.48; p < 0.001). We observed a higher VASC rate in FA patients in the contemporary cohort compared with the historical cohort (adjusted rates: 4.19% vs. 1.98%; OR: 2.16, 95% CI: 1.67 to 2.81; p < 0.001). This finding was consistent for both diagnostic and therapeutic catheterizations separately. The proportion of VASCs attributable to RA in the contemporary FA patients was estimated at 52.7%. CONCLUSIONS: In a contemporary population where both RA and FA were used, the safety benefit associated with RA is offset by a paradoxical increase in VASCs among FA patients. The existence of this radial paradox should be taken into consideration, especially among trainees and default radial operators.

Electrocardiographic and electrophysiological predictors of atrioventricular block after transcatheter aortic valve replacement.

BACKGROUND: Electrophysiological predictors of atrioventricular (AV) block after transcatheter aortic valve replacement (TAVR) are unknown. OBJECTIVE: We sought to assess the value of electrophysiology study before and after TAVR. METHODS: Seventy-five consecutive pacemaker-free patients undergoing TAVR at the Montreal Heart Institute were prospectively studied. RESULTS: Eleven patients (14.7%) developed AV block during the index hospitalization and 3 (4.0%) after hospital discharge over a median follow-up of 1.4 years (interquartile range 0.6-2.1 years). AV block developed in 5 of 6 patients with preprocedural right bundle branch block (83.3%), 8 of 30 patients with new-onset left bundle branch block (LBBB; 26.7%), and 1 of 7 patients with preexisting LBBB (14.3%). In multivariate analysis that considered all patients, the delta-HV interval (HV interval after TAVR minus HV interval before TAVR) was the only factor independently associated with AV block. In the subgroup of patients with new-onset LBBB, the postprocedural HV interval was strongly associated with AV block. By receiver operating characteristic analysis, a delta-HV interval of ≥13 ms predicted AV block with 100.0% sensitivity and 84.4% specificity and an HV interval of ≥65 ms predicted AV block with 83.3% sensitivity and 81.6% specificity. In multivariate analysis, the HV interval after TAVR (hazard ratio 1.073 per ms; 95% confidence interval 1.029-1.119; P = .001) was also independently associated with all-cause mortality. CONCLUSION: A prolonged delta-HV interval (≥13 ms) is strongly associated with AV block after TAVR. In patients with new-onset LBBB after TAVR, a postprocedural HV interval of ≥65 ms is likewise predictive of AV block.

Impact of coronary artery disease on left ventricular ejection fraction recovery following transcatheter aortic valve implantation.

OBJECTIVES: The objective of the present study was to assess if the presence and severity of CAD is associated with decreased LVEF recovery after TAVI. BACKGROUND: Coronary artery disease (CAD) and low left ventricular ejection fraction (LVEF) are common findings in patients undergoing transcatheter aortic valve implantation (TAVI). The impact of CAD on LVEF recovery after TAVI has not been specifically evaluated. METHODS: All patients with LVEF≤50% who underwent TAVI between March 2006 and May 2012 were included in the study. The presence and severity of coronary artery disease was measured using the Duke Myocardial Jeopardy Score (DMJS). A DMJS = 0 corresponds to patients without CAD or complete revascularization and a DMJS > 0 to those with incomplete revascularization. LVEF recovery was assessed by transthoracic echocardiography, measuring the change in LVEF from baseline to 3-months post-TAVI. Myocardial viability was evaluated in a subgroup of patients using cardiac magnetic resonance (CMR) imaging pre-TAVI. RESULTS: Fifty-six patients were included in the study. Twenty-eight patients (50%) had a DMJS > 0. At 3 months, patients with incomplete revascularization (DMJS > 0) demonstrated less LVEF recovery post-TAVI (2.0 ± 9.2% versus 11.7 ± 8.9% if DMJS = 0; P = 0.001). On multivariate analysis, DMJS and presence of significant delayed-enhancement were found to be independent predictors of LVEF recovery. Patients with incomplete revascularization exhibited a worse prognosis with higher mortality at 30-days (22.2% versus 0% if DMJS = 0; P = 0.010) and 1-year (25.9% versus 3.5% if DMJS = 0; P = 0.019). CONCLUSIONS: The present study demonstrates an independent association between incomplete revascularization and decreased LVEF recovery in patients with left ventricular dysfunction undergoing TAVI for severe aortic stenosis.

MitraClip intervention as rescue therapy in cardiogenic shock: one-year follow-up.

The MitraClip (Abbott Vascular, Menlo Park, CA) is a device used to perform transcatheter edge-to-edge repair of the mitral valve approved by the Food and Drug Administration for the treatment of high-risk degenerative mitral regurgitation. We describe the follow up of a 78-year-old man with severe functional mitral regurgitation and cardiogenic shock who underwent a successful MitraClip implantation.

Unusual coronary occlusion post transcatheter aortic implantation: the importance of clinical assessment.

Despite the increasing experience with transcatheter aortic valve implantation, the incidence of severe complications is still relevant. One of the most feared complications is coronary obstruction. This life-threatening complication, occurring in up to 1% of patients, might be catastrophic, presenting with hemodynamic instability but allowing for rapid detection and treatment. To date, all published cases have reported ostial occlusions of either the left main or the right coronary artery. We describe an uncommon presentation of distal right coronary artery obstruction post transcatheter aortic valve implantation that was diagnosed after the patient developed chest pain in the recovery room.

Histopathological effects and evolution of transvenous ß-radiation applications in right and left atria: an animal study.

AIMS: ß-radiation is a novel potential energy source for the creation of myocardial lesions. While the feasibility of delivering ß-radiation via a deflectable transvenous catheter has been described, dose effects and the time course of histopathological changes have not been previously assessed. The purpose of this study was to characterize pathological aspects of cardiac lesions induced by ß-radiation in an animal model at various stages of evolution and in response to different dose exposures. METHODS AND RESULTS: Nine dogs and one pig were studied. The cavotricuspid isthmus, antrum of pulmonary veins (PVs), and mitral isthmus were irradiated (25, 50, 75, or 100 Gy) with strontium-yttrium-90, delivered via a deflectable catheter (cavotricuspid isthmus and mitral isthmus) or a double-loop catheter (antrum of PVs). Eighteen lesions were created. Animals were sacrificed at 2 weeks, 1 month, 3 months, or 6 months. Lesions were processed for morphometric histopathological analyses. Over the first month, lesions were characterized by inflammation, haemorrhage, and myocyte necrosis. Thereafter, fibrotic replacement was predominant. Transmurality of lesions was observed in 50% of cases, with no dose-response effect (P = 0.976). Surface fibrin thrombus was present in 50% of cases and was essentially limited to lesions assessed within the first month. No neighbouring injury or pulmonary venous stenosis was observed. CONCLUSIONS: Atrial lesions created by ß-radiation are characterized by an inflammatory phase with surface fibrin thrombosis during the first month and replacement fibrosis thereafter. No appreciable dose-response effect was noted within the 25-100 Gy range tested.