Transcatheter Replacement of Stenotic Aortic Valve Normalizes Cardiac-Coronary Interaction by Restoration of Systolic Coronary Flow Dynamics as Assessed by Wave Intensity Analysis.

BACKGROUND: Aortic valve stenosis (AS) can cause angina despite unobstructed coronary arteries, which may be related to increased compression of the intramural microcirculation, especially at the subendocardium. We assessed coronary wave intensity and phasic flow velocity patterns to unravel changes in cardiac-coronary interaction because of transcatheter aortic valve implantation (TAVI). METHODS AND RESULTS: Intracoronary pressure and flow velocity were measured at rest and maximal hyperemia in undiseased vessels in 15 patients with AS before and after TAVI and in 12 control patients. Coronary flow reserve, systolic and diastolic velocity time integrals, and the energies of forward (aorta-originating) and backward (microcirculatory-originating) coronary waves were determined. Coronary flow reserve was 2.8±0.2 (mean±SEM) in control and 1.8±0.1 in AS (P<0.005) and was not restored by TAVI. Compared with control, the resting backward expansion wave was 45% higher in AS. The peak of the systolic forward compression wave was delayed in AS, consistent with a delayed peak aortic pressure, which was partially restored after TAVI. The energy of forward waves doubled after TAVI, whereas the backward expansion wave increased by >30%. The increase in forward compression wave with TAVI was related to an increase in systolic velocity time integral. AS or TAVI did not alter diastolic velocity time integral. CONCLUSIONS: Reduced coronary forward wave energy and systolic velocity time integral imply a compromised systolic flow velocity with AS that is restored after TAVI, suggesting an acute relief of excess compression in systole that likely benefits subendocardial perfusion. Vasodilation is observed to be a major determinant of backward waves.

Meta-analysis of predictors of all-cause mortality after transcatheter aortic valve implantation.

The aim of this study was to identify predictors of 30-day and midterm mortality after transcatheter aortic valve implantation (TAVI) by means of a systemic review. TAVI was demonstrated to be safe and efficacious in patients with severe aortic stenosis. An accurate estimation of procedural risk of these patients represents an actual challenge. The PubMed and Cochrane Collaboration databases were systematically searched for studies reporting on the incidence and independent predictors of 30-day and midterm mortality. Adverse events were pooled with random effect, whereas independent predictors are reported as odds ratios (ORs) with 95% confidence intervals (CIs). A total of 25 studies with 8,874 patients were included (median age 82.5 ± 1.5 years, 54.6% women). At 30 days, 7.5% of patients (n = 663) died. At midterm follow-up (median 365 days, interquartile range 267 to 365 days), the cumulative mortality rate was 21.6% (n = 1,917). Acute kidney injury (AKI) stage ≥2 (OR 18.0, 95% CI 6.3 to 52), preprocedural hospitalization for heart failure (OR 9.4, 95% CI 2.6 to 35), periprocedural acute myocardial infarction (OR 8.5, 95% CI 2.6 to 33.5), and increased pro-brain natriuretic peptide (pro-BNP) levels (OR 5.4, 95% CI 1.7 to 16.5) were the most important independent predictors of 30-day mortality. Increased pro-BNP levels (OR 11, 95% CI 1.5 to 81), AKI stage 3 (OR 6.8, 95% CI 2.6 to 15.7), left ventricular ejection fraction <30% (OR 6.7, 95% CI 3.5 to 12.7), and periprocedural acute myocardial infarction (OR 6.5, 95% CI 2.3 to 18.1) represented the predictors of midterm mortality. In conclusion, in this large meta-analysis of patients undergoing TAVI, we found that high pro-BNP levels and postprocedural AKI were the strongest independent predictors of both 30-day and 1-year mortality. These findings may contribute to a better understanding of the risk assessment process of patients undergoing TAVI.

Predictors and permanency of cardiac conduction disorders and necessity of pacing after transcatheter aortic valve implantation.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) with the Medtronic-CoreValve bioprosthesis (CoreValve Inc., Irvine, CA, USA) is associated with a high incidence of new-onset left bundle branch block (LBBB) and cardiac conduction disorders (CCDs) requiring permanent pacemaker (PPM) implantation. Our objective was to investigate the predictors and permanency of CCDs after TAVI and specifically to evaluate the necessity for pacing. METHODS: In this single-center study, we included patients who underwent TAVI with the Medtronic-CoreValve bioprosthesis. Electrocardiographic evaluation was performed pre- and post-TAVI and at follow-up. Pacemaker follow-up data were obtained and analyzed. RESULTS: We included 121 patients (age 81 ± 8 years). LBBB developed in 47 patients, for which prosthesis size (26 mm; odds ratio [OR]: 4.1, 95% confidence interval [CI]: 1.32-12.34, P = 0.01) and prosthesis depth (OR: 1.3, 95% CI: 1.09-1.57, P = 0.004) were independent predictors. In 19%, this new-onset LBBB was temporary. Requirement for a PPM occurred in 23 patients, for which mitral annular calcification (MAC; OR: 1.3, 95% CI: 1.05-1.56, P = 0.02) and preexisting right bundle branch block (RBBB; OR: 8.5, 95%CI: 1.61-44.91, P = 0.01) were independent predictors. At follow-up, 52% of the patients were continuously paced, but 22% of the patients had adequate atrioventricular conduction without the necessity for pacing. In the other 26% of the patients there was intermittent pacing. CONCLUSION: There is a high incidence of new-onset LBBB and PPM implantation following TAVI with a Medtronic-CoreValve bioprosthesis. Prosthesis depth and size were predictors for new LBBB, while MAC and preexistent RBBB were predictors for PPM implantation. In approximately one fifth of the patients, new-onset LBBB and the necessity for pacing are only temporary.

Predictors and prognostic value of myocardial injury during transcatheter aortic valve implantation.

BACKGROUND: Myocardial injury is a common complication during cardiac surgery and percutaneous coronary intervention and is associated with postprocedural cardiovascular morbidity and mortality. Limited data have been reported about the occurrence of myocardial damage associated with transcatheter aortic valve implantation (TAVI). Therefore, our purpose was to investigate the incidence, predictors, and prognostic value of myocardial injury during TAVI. METHODS AND RESULTS: We studied 119 patients (aged 81±8 years; 47 male) who had undergone a TAVI with the Medtronic-CoreValve bioprosthesis. Serum creatine kinase-MB (CK-MB) and cardiac troponin T (cTnT) levels were measured before and after the procedure. Myocardial injury was defined as a postprocedural increase of CK-MB and/or cTnT level >5 times the upper reference limit. After TAVI, the incidence of myocardial injury was 17%, which was independently predicted by procedural duration (in minutes) (odds ratio [OR], 1.04; 95% CI, 1.01-1.06), preprocedural ß-blocker use (OR, 0.12; 95% CI, 0.03-0.45), peripheral arterial disease (OR, 6.36; 95% CI, 1.56-25.87), and prosthesis depth (in millimeters) (OR, 1.31; 95% CI, 1.08-1.59). The 30-day mortality after TAVI was 13% and was independently predicted by myocardial injury (OR, 8.54; 95% CI, 2.17-33.52), preprocedural hospitalization (OR, 9.36; 95% CI, 2.55-34.38), and left ventricular mass index (in g/m(2)) (OR, 1.02; 95% CI, 1.00-1.03). CONCLUSIONS: After transcatheter aortic valve implantation, serum levels of both CK-MB and cTnT increase, reflecting the occurrence of periprocedural myocardial injury. A longer procedural duration, the absence of ß-blocker use, peripheral arterial disease, and a deeper prosthesis insertion are associated with myocardial injury. Together with preprocedural hospitalization and left ventricular mass, myocardial injury is an independent predictor for 30-day mortality after TAVI.

Right ventricular pacing improves haemodynamics in right ventricular failure from pressure overload: an open observational proof-of-principle study in patients with chronic thromboembolic pulmonary hypertension.

AIMS: Right ventricular (RV) failure in patients with chronic thromboembolic pulmonary hypertension (CTEPH), and other types of pulmonary arterial hypertension is associated with right-to-left ventricle (LV) delay in peak myocardial shortening and, consequently, the onset of diastolic relaxation. We aimed to establish whether RV pacing may resynchronize the onsets of RV and LV diastolic relaxation, and improve haemodynamics. METHODS AND RESULTS: Fourteen CTEPH patients (mean age 63.7 ± 12.0 years, 10 women) with large (≥60 ms) RV-to-LV delay in the onset of diastolic relaxation (DIVD, diastolic interventricular delay) were studied. Temporary RV pacing was performed by atrioventricular (A-V) sequential pacing with incremental shortening of A-V delay to advance RV activation. Effects were assessed using tissue Doppler echocardiography and LV pressure-conductance catheter measurements in a subset of patients. Compared with right atrial pacing, RV pacing at optimal A-V delay (average 140 ± 22 ms, range 120-180 ms) resulted in significant DIVD reduction (59 ± 19 to 3 ± 22 ms, P < 0.001), and increase in LV stroke volume as measured by LV outflow tract velocity-time integral (14.9 ± 2.8 to 16.9 ± 3.0 cm, P < 0.001), along with enhanced global RV contractility and LV diastolic filling. CONCLUSION: Right-to-left ventricle resynchronization of the onset of diastolic relaxation results in stroke volume increase in CTEPH patients. Whether RV pacing may be a novel therapeutic target in RV failure following chronic pressure overload remains to be investigated.

More pronounced diastolic left ventricular dysfunction in patients with accelerated idioventricular rhythm after reperfusion by primary percutaneous coronary intervention.

OBJECTIVE: Reperfusion-induced accelerated idioventricular rhythm (AIVR) during primary percutaneous coronary intervention (pPCI) may be a sign of left ventricular (LV) dysfunction. We compared LV dynamic effects of reperfusion between patients with and without reperfusion-induced AIVR during pPCI for ST-elevation myocardial infarction (STEMI). METHODS: We studied 15 consecutive patients, who presented with their first acute anterior STEMI within 6 hours after onset of symptoms, and in whom LV pressure-volume (PV) loops were directly obtained during pPCI. Immediate effects of pPCI on LV function were compared between patients with (n = 5) and without (n = 10) occurrence of AIVR after reperfusion, as well as the direct effects of AIVR on LV function compared to sinus rhythm. RESULTS: Patients with reperfusion-induced AIVR showed more pronounced diastolic LV dysfunction before the onset of the arrhythmia, i.e., a delayed active relaxation expressed by Tau (53 ± 15 vs. 39 ± 6 ms; p = 0.03), a worse compliance curve (p = 0.01), and a higher end-diastolic stiffness (p = 0.07). At the end of the procedure, AIVR patients showed less improvement in diastolic LV function, indicated by a downward shift of the compliance curve (-3.1 ± 2.3 vs. -7.5 ± 1.4 mmHg; p = 0.001), a decrease in end-diastolic stiffness (13 ± 18 vs. 34 ± 15%; p = 0.03) and end-diastolic pressure (12 ± 8 vs. 29 ± 19%; p = 0.07). CONCLUSION: STEMI patients with reperfusion-induced AIVR after pPCI showed more pronounced diastolic LV dysfunction before and after AIVR than patients without AIVR, which suggests that diastolic LV dysfunction contributes to the occurrence of AIVR and that AIVR is a sign of diastolic LV dysfunction.

Improvement of sidestream dark field imaging with an image acquisition stabilizer.

BACKGROUND: In the present study we developed, evaluated in volunteers, and clinically validated an image acquisition stabilizer (IAS) for Sidestream Dark Field (SDF) imaging. METHODS: The IAS is a stainless steel sterilizable ring which fits around the SDF probe tip. The IAS creates adhesion to the imaged tissue by application of negative pressure. The effects of the IAS on the sublingual microcirculatory flow velocities, the force required to induce pressure artifacts (PA), the time to acquire a stable image, and the duration of stable imaging were assessed in healthy volunteers. To demonstrate the clinical applicability of the SDF setup in combination with the IAS, simultaneous bilateral sublingual imaging of the microcirculation were performed during a lung recruitment maneuver (LRM) in mechanically ventilated critically ill patients. One SDF device was operated handheld; the second was fitted with the IAS and held in position by a mechanic arm. Lateral drift, number of losses of image stability and duration of stable imaging of the two methods were compared. RESULTS: Five healthy volunteers were studied. The IAS did not affect microcirculatory flow velocities. A significantly greater force had to applied onto the tissue to induced PA with compared to without IAS (0.25 +/- 0.15 N without vs. 0.62 +/- 0.05 N with the IAS, p < 0.001). The IAS ensured an increased duration of a stable image sequence (8 +/- 2 s without vs. 42 +/- 8 s with the IAS, p < 0.001). The time required to obtain a stable image sequence was similar with and without the IAS. In eight mechanically ventilated patients undergoing a LRM the use of the IAS resulted in a significantly reduced image drifting and enabled the acquisition of significantly longer stable image sequences (24 +/- 5 s without vs. 67 +/- 14 s with the IAS, p = 0.006). CONCLUSIONS: The present study has validated the use of an IAS for improvement of SDF imaging by demonstrating that the IAS did not affect microcirculatory perfusion in the microscopic field of view. The IAS improved both axial and lateral SDF image stability and thereby increased the critical force required to induce pressure artifacts. The IAS ensured a significantly increased duration of maintaining a stable image sequence.

Factors associated with cardiac conduction disorders and permanent pacemaker implantation after percutaneous aortic valve implantation with the CoreValve prosthesis.

BACKGROUND: Cardiac conduction disorders and requirement for permanent pacemaker implantation (PPI) are not uncommon after surgical aortic valve replacement and have important clinical implications. We aimed to investigate the incidence of cardiac conduction disorders after percutaneous aortic valve implantation (PAVI) and to identify possible clinical factors associated with their development. METHODS: We studied 34 patients (mean age 80 +/- 8 years, 18 male) who underwent PAVI with the CoreValve bioprosthesis (Corevalve Inc, Irvine, CA). Electrocardiographic evaluation was performed pre- and postprocedurally, and at 1-week and 1-month follow-up. Other clinical variables were obtained from the medical history, echocardiography, and angiography. RESULTS: After PAVI, 7 patients required PPI, all of whom developed total atrioventricular block within 3 days postprocedurally. A smaller left ventricular outflow tract diameter (20.3 +/- 0.5 vs 21.6 +/- 1.8 cm, P = .01), more left-sided heart axis (-20 degrees +/- 29 degrees vs 19 degrees +/- 36 degrees , P = .02), more mitral annular calcification (10 +/- 1 vs 5 +/- 4 mm, P = .008), and a smaller postimplantation indexed effective orifice area (0.86 +/- 0.20 vs 1.10 +/- 0.26 cm(2)/m(2), P = .04) were associated with PPI. The incidence of new left bundle-branch block (LBBB) was 65% and was associated with a deeper implantation of the prosthesis: 10.2 +/- 2.3 mm in the new-LBBB group versus 7.7 +/- 3.1 mm in the non-LBBB group (P = .02). CONCLUSIONS: Percutaneous aortic valve implantation with the CoreValve prosthesis results in a high incidence of total atrioventricular block requiring PPI and new-onset LBBB. Preexisting disturbance of cardiac conduction, a narrow left ventricular outflow tract, and the severity of mitral annular calcification predict the need for permanent pacing, whereas the only factor shown to be predictive for new-onset LBBB is the depth of prosthesis implantation.