Multicenter Comparison of Novel Self-Expanding Versus Balloon-Expandable Transcatheter Heart Valves.

OBJECTIVES: This study sought to compare 2 next-generation transcatheter heart valves (THV), the self-expanding ACURATE neo (NEO) and the balloon-expandable SAPIEN 3 (S3), in terms of device failure and early safety at 30 days. BACKGROUND: Deployment of these THV showed promising initial clinical results. However, no comparative data are available. METHODS: Of 1,121 treated patients at 3 centers, a 1-to-2 nearest neighbor matching was performed to identify 2 patients treated with S3 (n = 622) for each patient treated with NEO (n = 311). RESULTS: In-hospital complications were comparable between NEO and S3, including stroke (1.9% vs. 2.4%; p = 0.64), major vascular complications (10.3% vs. 8.5%; p = 0.38), or life-threatening bleeding (4.2% vs. 3.7%; p = 0.72). Device failure with NEO was comparable with S3 (10.9% vs. 9.6%; odds ratio: 1.09 [95% confidence interval: 0.69 to 1.73]; p = 0.71) with more paravalvular leakage (PVL II+, 4.8% vs. 1.8%; p = 0.01), but less elevated gradients (≥20 mm Hg, 3.2% vs. 6.9%; p = 0.02) and pacemaker implantations (9.9% vs. 15.5%; p = 0.02). Thirty-day mortality (2.3% vs. 1.9%; p = 0.74) and the early safety composite endpoint (15.8% vs. 15.6%; hazard ratio: 0.97 [95% confidence interval: 0.68 to 1.39]; p = 0.88) were similar with NEO and S3. CONCLUSIONS: Very high success rates were achieved for both valves, and the clinical and procedural results were comparable. Compared with S3, NEO was associated with less new pacemaker implantations and less elevated gradients, but with more paravalvular leakage.

Effects of respiratory mechanics on the capnogram phases: importance of dynamic compliance of the respiratory system.

INTRODUCTION: The slope of phase III of the capnogram (SIII) relates to progressive emptying of the alveoli, a ventilation/perfusion mismatch, and ventilation inhomogeneity. S(III) depends not only on the airway geometry, but also on the dynamic respiratory compliance (Crs); this latter effect has not been evaluated. Accordingly, we established the value of SIII for monitoring airway resistance during mechanical ventilation. METHODS: Sidestream capnography was performed during mechanical ventilation in patients undergoing elective cardiac surgery (n = 144). The airway resistance (Raw), total respiratory resistance and Crs displayed by the ventilator, the partial pressure of arterial oxygen (PaO2) and S(III) were measured in time domain (S(T-III)) and in a smaller cohort (n = 68) by volumetry (S(V-III)) with and without normalization to the average CO2 phase III concentration. Measurements were performed at positive end-expiratory pressure (PEEP) levels of 3, 6 and 9 cmH2O in patients with healthy lungs (Group HL), and in patients with respiratory symptoms involving low (Group LC), medium (Group MC) or high Crs (Group HC). RESULTS: S(T-III) and S(V-III) exhibited similar PEEP dependencies and distribution between the protocol groups formed on the basis of Crs. A wide interindividual scatter was observed in the overall Raw-S(T-III) relationship, which was primarily affected by Crs. Decreases in Raw with increasing PEEP were reflected in sharp falls in S(III) in Group HC, and in moderate decreases in S(III) in Group MC, whereas S(T-III) was insensitive to changes in airway caliber in Groups LC and HL. CONCLUSIONS: SIII assessed in the time domain and by volumetry provide meaningful information about alterations in airway caliber, but only within an individual patient. Although S(T-III) may be of value for bedside monitoring of the airway properties, its sensitivity depends on Crs. Thus, assessment of the capnogram shape should always be coupled with Crs when the airway resistance or oxygenation are evaluated.