The impact of moderate Aortic Valve Disease in patients undergoing MitraClip for severe MR.

BACKGROUND: High surgical risk patients presenting with severe mitral valve regurgitation (MR) and concomitant aortic valve disease are frequently a challenge for the interdisciplinary heart team meeting. If open-heart surgery for severe MR is performed, aortic stenosis (AS) or regurgitation (AR) is corrected during the same procedure if at least moderate severity of AS or AR has been confirmed. In patients with prohibitive surgical risk, optimal management strategies in the light of available transcatheter interventions still needs to be established. METHODS AND RESULTS: In this retrospective single center study, we aimed to investigate the impact of coincident moderate aortic valve disease on the outcome of patients undergoing MitraClip for severe MR. In 286 MitraClip procedures performed in our institution, 21 patients (7,3%) were identified to suffer from concomitant moderate AS and 28 patients had moderate AR (9,8%). Patients with AS were found to have a higher incidence of >moderate MR following the procedure when compared to patients without aortic valve disease (14,3% vs. 8,9%, p = 0.001). No differences between the groups were found regarding a combined endpoint of all cause deaths and heart failure hospitalizations after 1 year follow up (no aortic-valve disease vs. moderate AS: 19% vs 18%; p = 0,881 and no aortic valve disease vs moderate AR: 19% vs. 25%; p = 0.477). However, mortality was significantly higher in patients with coincidental moderate AR (3.8% patients without aortic valve disease, 5% in patients with AS, 17,9% in patients with AR; p = 0.006). CONCLUSION: According to our analysis coincidental Aortic valve stenosis may be associated with worse technical results regarding residual MR after MitraClip. Although our results regarding a combined endpoint of all-cause mortality and heart failure hospitalizations within one year of follow up were comparable between the groups, patients with moderate AR had significantly higher mortality rates. Due to the limited number of patients, our study is only hypothesis generating. Larger trials are necessary to confirm our result.

The MitraClip Procedure in Patients With Moderate Resting but Severe Exercise-Induced Mitral Regurgitation.

BACKGROUND: Optimal timing for percutaneous mitral regurgitation (MR) treatment using MitraClip (Abbott Vascular) remains unclear. We evaluated the outcome after MitraClip in patients with moderate resting MR, progressing to severe exercise- induced MR (MR2+) compared to patients with severe resting MR (MR3). METHODS: We retrospectively investigated 221 patients undergoing MitraClip. All-cause deaths and heart failure (HF) hospitalizations were assessed as the combined primary endpoint. RESULTS: We identified 55 MR2+ and 166 MR3 patients. At baseline, MR3 patients showed higher STS scores (6.7 ± 7.3 vs 4.4 ± 5.5; P<.01), more HF hospitalizations in the 2 years prior to the procedure (51% vs 29%; P<.01), worse left ventricular ejection fraction (44.9 ± 16.5% vs 52.5 ± 14.3%; P<.01), larger left ventricular end-diastolic diameter (LVEDd; 57.0 ± 9.3 mm vs 51.7 ± 8.2 mm; P<.001), and larger left atrial volumes (118.3 ± 55.8 mL vs 98.6 ± 35.2 mL; P=.02). Long-term outcome according to the combined endpoint was significantly worse in MR3 patients (P=.01). HF hospitalizations significantly declined in both groups 2 years after MitraClip (P<.001 in MR3 patients, P=.03 in MR2+ patients). Multivariate Cox regression analysis revealed LVEDd (hazard ratio, 1.035; 95% confidence interval, 1.005-1.066; P=.02) and previous HF hospitalizations (hazard ratio, 1.813; 95% confidence interval, 1.016-3.234; P=.04) as strong outcome predictors. CONCLUSIONS: Symptomatic patients with moderate resting and severe exercise-induced MR during handgrip echocardiography may represent an MR cohort at an earlier disease stage with improved treatment response following MitraClip implantation compared to individuals with severe resting MR. Larger left ventricular diameters and preprocedural HF hospitalizations were identified as independent adverse outcome predictors.

Shear-induced platelet adherence and activation in an in-vitro dynamic multiwell-plate system.

Circulating blood cells are prone to varying flow conditions when contacting cardiovascular devices. For a profound understanding of the complex interplay between the blood components/cells and cardiovascular implant surfaces, testing under varying shear conditions is required. Here, we study the influence of arterial and venous shear conditions on the in vitro evaluation of the thrombogenicity of polymer-based implant materials.Medical grade poly(dimethyl siloxane) (PDMS), polyethylene terephthalate (PET) and polytetrafluoroethylene (PTFE) films were included as reference materials. The polymers were exposed to whole blood from healthy humans. Blood was agitated orbitally at low (venous shear stress: 2.8 dyne · cm-2) and high (arterial shear stress: 22.2 dyne · cm-2) agitation speeds in a well-plate based test system. Numbers of non-adherent platelets, platelet activation (P-Selectin positive platelets), platelet function (PFA100 closure times) and platelet adhesion (laser scanning microscopy (LSM)) were determined.Microscopic data and counting of the circulating cells revealed increasing numbers of material-surface adherent platelets with increasing agitation speed. Also, activation of the platelets was substantially increased when tested under the high shear conditions (P-Selectin levels, PFA-100 closure times). At low agitation speed, the platelet densities did not differ between the three materials. Tested at the high agitation speed, lowest platelet densities were observed on PDMS, intermediate levels on PET and highest on PTFE. While activation of the circulating platelets was affected by the implant surfaces in a similar manner, PFA closure times did not reflect this trend.Differences in the thrombogenicity of the studied polymers were more pronounced when tested at high agitation speed due to the induced shear stresses. Testing under varying shear stresses, thus, led to a different evaluation of the implant thrombogenicity, which emphasizes the need for testing under various flow conditions. Our data further confirmed earlier findings where the same reference implants were tested under static (and not dynamic) conditions and with fresh human platelet rich plasma instead of whole blood. This supports that the application of common reference materials may improve inter-study comparisons, even under varying test conditions.

The predictive value of a modified Carpentier classification in patients with coincidental mitral regurgitation undergoing TAVI for severe aortic valve stenosis1.

INTRODUCTION: Concomitant mitral-regurgitation (MR) is frequently observed in patients undergoing trans-catheter aortic valve implantation (TAVI). The predictive value of MR etiology remains to be elucidated. METHODS: 600 patients with coincidental MR (≥moderate) undergoing TAVI were categorized according to a modified Carpentier classification [Groups: no/mild MR, n = 477; left atrial (LA) functional MR, n = 18; MR due to left ventricular dilatation, n = 29; degenerative MR, n = 50; MR with restricted leaflet motion n = 26]. MR improvement and patient outcome was compared among the groups in a retrospective analysis. RESULTS: MR regression was most pronounced in patients with restricted leaflet motion after 6 months, although a significant improvement was observed in all subgroups. MR relief was predominantly observed within the first 30 days after TAVI. Only patients with restricted leaflet motion experienced further improvement thereafter.In the entire cohort a total of 15 strokes (2.5%) during the first 30 days after TAVI were observed, with the highest incidence in the LA functional cohort (3 events, 17%; p = 0.008). In multivariate analysis, organic etiology was associated with an increased 1-year mortality.In conclusion, despite significant MR regression in all MR groups, some individuals may require additional mitralvalve repair after TAVI. According to our data the timing of these procedures should be based on the underlying MR etiology. The Carpentier classification in patients with coincidental MR undergoing TAVI for severe AS may also have prognostic implications as we found an increased incidence of strokes in our LA functional cohort and a worse mortality rates in organic MR.

Repeated MitraClip procedure in patients with recurrent MR after a successful first procedure: Limitations and outcome.

OBJECTIVES: The present study aimed to evaluate the outcome and potential limitations of a repeated MitraClip procedure (ReClip). BACKGROUND: The MitraClip procedure has emerged as a treatment option in high surgical risk patients suffering from severe mitral regurgitation (MR). However, despite successful initial repair a significant number of patients develops severe recurrent MR. METHODS: Patients undergoing a ReClip procedure in our institution were retrospectively identified. Baseline data and the procedural outcome were assessed to identify potential limitations of such procedures. RESULTS: Fifteen out of 234 patients undergoing a mitral-valve repair with the MitraClip device (Abbott Vascular) underwent a ReClip due to recurrent MR. In 11 patients, a MR reduction of at least one degree without causing mitral valve stenosis (trans-mitral mean gradient ≥5 mmHg) was achieved by performing a ReClip. After 1 year, two patients developed severe recurrent MR again. Pulmonary artery pressures significantly decreased after the procedure in individuals with successful repair (MR reduction of at least one degree and mitral valve mean gradient <5 mmHg). CONCLUSION: A ReClip procedure may be feasible in patients with recurrent MR but the risk benefit ratio should be carefully balanced against other treatment options.