Relation Between Left Ventricular Outflow Tract Calcium and Mortality Following Transcatheter Aortic Valve Implantation

Left ventricular outflow tract (LVOT) calcium is known to be associated with adverse procedural outcomes after transcatheter aortic valve implantation (TAVI), yet its effect on midterm outcomes has not been previously investigated. The aim of this study was to determine the influence of LVOT calcium on 2-year mortality after TAVI. A total of 537 consecutive patients underwent TAVI and 2 groups were established, stratified based on the severity of the LVOT calcium. The primary outcome was 2-year overall survival rate. The ≥moderate LVOT calcium group included 107 patients (19.9%) and the remaining 430 patients (80.1%) were included in the ≤mild LVOT calcium group. After a median follow-up of 717 days (interquartile range 484 to 828), the Kaplan-Meier analysis revealed that the 2-year overall survival probability was significantly lower in the ≥moderate LVOT calcium group than in the ≤mild LVOT calcium group (log-rank p = 0.001). On a Cox hazard model, ≥moderate LVOT calcium was associated with increased all-cause mortality after TAVI (hazard ratio 1.74, p = 0.009). In the subgroup analysis, based on valve designs, SAPIEN 3-TAVI done in the setting of ≥moderate LVOT calcium had a relatively similar survival probability as those of ≤mild LVOT calcium (log-rank p = 0.18), which is in contrast with older generation valves (log-rank p = 0.001). In conclusion, patients with ≥moderate LVOT calcium were shown to have a lower survival probability in the midterm follow-up after TAVI, compared with those with ≤mild LVOT calcium. Patients with high-grade LVOT calcium should be monitored with longer-term follow-ups after TAVI.

A Highly Predictive Risk Model for Pacemaker Implantation After TAVR

OBJECTIVES

This study sought to develop a robust and definitive risk model for new permanent pacemaker implantation (PPMI) after SAPIEN 3 (third generation balloon expandable valve) (Edwards Lifesciences, Irvine, California) transcatheter aortic valve replacement (third generation balloon expandable valve TAVR), including calcification in the aortic-valvular complex (AVC).

BACKGROUND

The association between calcium in the AVC and need for PPMI is poorly delineated after third generation balloon expandable valve TAVR.

METHODS

At Cedars-Sinai Heart Institute in Los Angeles, California, a total of 240 patients with severe aortic stenosis underwent third generation balloon expandable valve TAVR and had contrast computed tomography. AVC was characterized precisely by leaflet sector and region.

RESULTS

The total new PPMI rate was 14.6%. On multivariate analysis for predictors of PPMI, pre-procedure third generation balloon expandable valve TAVR, right bundle branch block (RBBB), shorter membranous septum (MS) length, and noncoronary cusp device-landing zone calcium volume (NCC-DLZ CA) were included. Predictive probabilities were generated using this logistic regression model. If 3 pre-procedural risk factors were present, the c-statistic of the model for PPMI was area under the curve of 0.88, sensitivity of 77.1%, and specificity of 87.1%; this risk model had high negative predictive value (95.7%). The addition of the procedural factor of device depth to the model, with the parameter of difference between implantation depth and MS length, combined with RBBB and NCC-DLZ CA increased the c-statistic to 0.92, sensitivity to 94.3%, specificity to 83.8%, and negative predictive value to 98.8% CONCLUSIONS: By using a precise characterization of distribution of calcification in the AVC in a single-center, retrospective study, NCC-DLZ CA was found to be an independent predictor of new PPMI post-third generation balloon expandable valve TAVR. The findings also reinforce the importance of short MS length, pre-existing RBBB, and ventricular implantation depth as important synergistic PPMI risk factors. This risk model will need validation by future prospective multicenter studies.

ANTIOXIDANT, ANTIBACTERIAL AND GUT MODULATING ACTIVITIES OF KALANCHOE LACINIATA

Kalanchoe laciniata (L.) DC. (Crassulaceae) is a widely distributed plant in Africa and Asia. Traditionally, various communities use this plant for the treatment of a variety of ailments such as gut prob- lems, allergic conditions and wounds. The current study was designed to explore the antibacterial, antioxidant and gut modulating activities of K. laciniata in order to provide scientific rationale for its traditional uses. Phytochemical compounds were assessed through screening 70% crude methanolic extract of K. laciniata. Its gut modulatory activity was evaluated by in vitro tissue experiments on rabbit jejunum which yielded maximal spasmogenic response of 28.4 ± 4.6% (n = 4) at 3 mg/mL, while spasmolytic response was recorded with EC50 value of 3.2 mg/mL (2.8-3.5, 95% CI, n = 5). In antibacterial assays crude extract was found effective against Stapllococcus aurus and Bacillus subtilis, with MIC value of 5 and 2.5 mg/mL, respectively. The testing of the methanolic crude extract for antioxidants resulted in total phenolic contents of 27.8 ± 1.8 mg GAE/g DW and 22.7 ± 2.1 mg AAE/g DW total antioxidant activity. It also scavenged 17.3 ± 3.0% of DPPH free radical when compared with quercitin.

Comparison of SAPIEN 3 and SAPIEN XT transcatheter heart valve stent-frame expansion: evaluation using multi-slice computed tomography

AIMS

Stent-frame morphology of the newer-generation, balloon-expandable transcatheter heart valve (THV), the SAPIEN 3 (S3), after transcatheter aortic valve implantation (TAVI) is unknown. We evaluated the THV stent-frame morphology post TAVI of the S3 using multi-slice computed tomography (MSCT) compared with the prior-generation THV, SAPIEN XT (S-XT).

METHODS AND RESULTS

A total of 94 consecutive participants of RESOLVE registry (NCT02318342) had MSCT after balloon-expandable TAVI (S3 = 39 and S-XT = 55). The morphology of the THV stent-frame was evaluated for expansion area and eccentricity at the THV-inflow, native annulus, mid-THV and THV-outflow levels. Mean %-expansion area for the S3 and the S-XT was 100.9 ± 5.7 and 96.1 ± 5.5%, respectively (P < 0.001). In the S3 group, the THV-inflow level had the largest value of %-expansion area, which decreased from THV-inflow to mid-THV level (105.2 ± 6.4 to 96.5 ± 5.9%, P < 0.001). However, in the S-XT group, %-expansion area increased from THV-inflow level to mid-THV level (93.2 ± 6.2 to 95.1 ± 6.1%, P = 0.0058). On nominal delivery balloon volume, the S3 in 88.5% of cases had overexpansion at the THV-inflow level. The observed degree of THV oversizing of the S3 was significantly lower than the S-XT (6.3 ± 8.6 vs. 11.8 ± 8.5%, P = 0.0027). Nonetheless, the incidence of post-procedural paravalvular aortic regurgitation (PVR) ≥ mild following the S3 TAVI was also significantly lower than the S-XT TAVI (17.9 vs. 43.6%, P = 0.014).

CONCLUSION

The newer-generation, balloon-expandable device, the S3, has a flared inflow morphology, whereas the prior-generation device, the S-XT, has relatively constrained inflow morphology post TAVI. This may contribute to a lesser degree of PVR with the S3.

Possible Subclinical Leaflet Thrombosis in Bioprosthetic Aortic Valves

BACKGROUND

A finding of reduced aortic-valve leaflet motion was noted on computed tomography (CT) in a patient who had a stroke after transcatheter aortic-valve replacement (TAVR) during an ongoing clinical trial. This finding raised a concern about possible subclinical leaflet thrombosis and prompted further investigation.

METHODS

We analyzed data obtained from 55 patients in a clinical trial of TAVR and from two single-center registries that included 132 patients who were undergoing either TAVR or surgical aortic-valve bioprosthesis implantation. We obtained four-dimensional, volume-rendered CT scans along with data on anticoagulation and clinical outcomes (including strokes and transient ischemic attacks [TIAs]).

RESULTS

Reduced leaflet motion was noted on CT in 22 of 55 patients (40%) in the clinical trial and in 17 of 132 patients (13%) in the two registries. Reduced leaflet motion was detected among patients with multiple bioprosthesis types, including transcatheter and surgical bioprostheses. Therapeutic anticoagulation with warfarin, as compared with dual antiplatelet therapy, was associated with a decreased incidence of reduced leaflet motion (0% and 55%, respectively, P=0.01 in the clinical trial; and 0% and 29%, respectively, P=0.04 in the pooled registries). In patients who were reevaluated with follow-up CT, restoration of leaflet motion was noted in all 11 patients who were receiving anticoagulation and in 1 of 10 patients who were not receiving anticoagulation (P<0.001). There was no significant difference in the incidence of stroke or TIA between patients with reduced leaflet motion and those with normal leaflet motion in the clinical trial (2 of 22 patients and 0 of 33 patients, respectively; P=0.16), although in the pooled registries, a significant difference was detected (3 of 17 patients and 1 of 115 patients, respectively; P=0.007).

CONCLUSIONS

Reduced aortic-valve leaflet motion was shown in patients with bioprosthetic aortic valves. The condition resolved with therapeutic anticoagulation. The effect of this finding on clinical outcomes including stroke needs further investigation. (Funded by St. Jude Medical and Cedars-Sinai Heart Institute; Portico-IDE ClinicalTrials.gov number, NCT02000115; SAVORY registry, NCT02426307; and RESOLVE registry, NCT02318342.).

Sphingosine-1-phosphate signaling: unraveling its role as a drug target against infectious diseases

Sphingosine-1-phosphate (S1P) signaling is reported in variety of cell types, including immune, endothelial and cancerous cells. It is emerging as a crucial regulator of cellular processes, such as apoptosis, cell proliferation, migration, differentiation and so on. This signaling pathway is initiated by the intracellular production and secretion of S1P through a cascade of enzymatic reactions. Binding of S1P to different S1P receptors (S1PRs) activates different downstream signaling pathways that regulate the cellular functions differentially depending upon the cell type. An accumulating body of evidence suggests that S1P metabolism and signaling is often impaired during infectious diseases; thus, its manipulation might be helpful in the treatment of such diseases. In this review, we summarize recent advances in our understanding of the S1P signaling pathway and its candidature as a novel drug target against infectious diseases.