Roberto Scarsini

Functional Assessment of Coronary Artery Disease in Patients Undergoing Transcatheter Aortic Valve Implantation: Influence of Pressure Overload on the Evaluation of Lesions Severity

Background—Aortic valve stenosis may influence fractional flow reserve (FFR) of concomitant coronary artery disease by causing hypertrophy and reducing the vasodilatory reserve of the coronary circulation. We sought to investigate whether FFR values might change after valve replacement. Methods and Results—The functional relevance of 133 coronary lesions was assessed by FFR in 54 patients with severe aortic valve stenosis before and after transcatheter aortic valve implantation (TAVI) during the same procedure. A linear mixed model was used to verify the interaction of TAVI effect with the FFR values. No significant overall change in FFR values was found before and after the aortic valve stenosis removal (0.89±0.10 versus 0.89±0.13; P=0.73). A different trend in FFR groups (positive if ⩽0.8; negative if >0.8) was found after TAVI (P for interaction <0.001). Positive FFR values worsened after TAVI (0.71±0.11 versus 0.66±0.14). Conversely, negative FFR values improved after TAVI (0.92±0.06 versus 0.93±0.07). Similarly, FFR values in coronary arteries with lesions presenting percent diameter stenosis >50 worsened after TAVI (0.84±0.12 versus 0.82±0.16; P=0.02), whereas FFR values in arteries with mild lesions (percent diameter stenosis <50) tended toward improvement after TAVI (0.90±0.07 versus 0.91±0.09; P=0.69). Functional FFR variations after TAVI changed the indication to treat the coronary stenosis in 8 of 133 (6%) lesions. Conclusions—Coronary hemodynamics are influenced by aortic valve stenosis removal. Nevertheless, FFR variations after TAVI are minor and crossed the diagnostic cutoff of 0.8 in a small number of patients after valve replacement. Borderline coronary lesions might become functionally significant after valve replacement, although FFR-guided interventions were infrequent even in patients with angiographically significant lesions.

Coronary Catheterization and Percutaneous Interventions After Transcatheter Aortic Valve Implantation

Coronary artery disease (CAD) is often present in patients with severe aortic valve stenosis candidates to transcatheter aortic valve implantation (TAVI). Mild CAD may also worsen and need treatment years after TAVI. The implantation of a transcatheter valve may interfere with the capability of reengaging the coronary arteries. We prospectively assessed the feasibility of performing coronary angiography (CA), fractional flow reserve, and, where indicated, percutaneous coronary intervention after valve implantation in a consecutive series of patients with CAD undergoing TAVI. Valve type and size were decided according to accurate computed tomography scan and angiographic measurement of the aortic root structures. We analyzed 66 consecutive patients undergoing TAVI, 41 with balloon-expandable, and 25 with self-expandable transcatheter valves. Right and left coronary catheterization (132 vessels) was successful in all cases except in 1 left coronary artery after a high implantation of a self-expandable valve (unsuccess rate, 1 in 50 vessels). In 6 of 132 vessels (4%), CA was initially nonselective, but after positioning the 0.014″ intracoronary guidewire, selective injections were obtained in all these cases. Percutaneous coronary intervention was performed successfully in 19 coronary vessels (17 patients) as indicated by fractional flow reserve measurements. In conclusion, catheterization of the coronary ostia after transfemoral TAVI with balloon or self-expandable valves is safe and feasible in almost all cases. Accurate imaging of the aortic root and procedural planning may help to avoid too high implantation of supra-annular self-expandable valves to obviate difficulties in accessing coronary ostia. Use of intracoronary guidewires facilitates selective CA in cases with difficult access.

Repeat revascularization: Percutaneous coronary intervention after coronary artery bypass graft surgery

Repeat myocardial revascularization procedures are markedly different from de novo interventions, with increased procedural risk and technical-demanding complexity. However the number of patients previously treated with coronary artery bypass graft (CABG) that need a repeat revascularization due to graft failure is increasing consistently. Late graft failure, usually caused by saphenous vein grafts (SVG) attrition, is certainly not uncommon. However PCI on degenerated SVG presents higher complication rate and worse clinical outcome compared with native arteries interventions. In acute graft failure setting, PCI represents a valuable option to treat postoperative myocardial infarction.

Physiologic evaluation of coronary lesions using instantaneous wave-free ratio (iFR) in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation

AIMS We sought to assess eventual changes in iFR measurements in patients with aortic stenosis (AS) before and after TAVI in coronary lesions with different degrees of angiographic severity. METHODS AND RESULTS The functional relevance of 145 coronary lesions was assessed by online iFR and FFR measurement in 66 patients with severe AS before and after TAVI, during the same procedure. The iFR-FFR classification agreement was calculated for pre-TAVI and post-TAVI measurements. Mean iFR values remained identical before and after TAVI, irrespective of the angiographic severity of the coronary stenosis (0.89±0.12 vs. 0.89±0.12, p=0.66). However, individual iFR values varied widely after TAVI and the 0.89 iFR threshold was crossed by 15% of the investigated coronary lesions. Higher iFR variation was related to a higher transaortic gradient drop after valve intervention. The diagnostic accuracy of iFR in predicting an FFR ≤0.8 was poor (65%) in lesions with severe obstructions, and tended to increase post TAVI. CONCLUSIONS Although overall values did not change after TAVI, iFR presented significant and mostly erratic individual variations after valve replacement. Delta iFR was influenced by the extent of the transaortic gradient drop induced by TAVI. Therefore, caution is advisable in the interpretation of iFR in the presence of AS.

Coronary physiology in patients with severe aortic stenosis: Comparison between fractional flow reserve and instantaneous wave-free ratio

BACKGROUND The functional assessment of coronary artery disease (CAD) in patients with aortic stenosis (AS) has not been validated so far, and the best strategy to physiologically investigate the relevance of coronary stenosis in this specific setting of patients remains undetermined. The aim of the study is to compare the diagnostic performance of instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) in patients with severe AS. METHODS The functional significance of 179 coronary lesions was investigated with on-line iFR and FFR measurements in 85 AS patients and compared with a control group formed by 167 patients (290 lesions) with stable CAD and without AS. The iFR-FFR diagnostic agreement has been tested using the conventional 0.80 FFR cut-off. RESULTS The correlation between iFR and FFR was similar between AS and CAD patients, as well as the area under the curve at ROC curve analysis (0.97 vs 0.96, p=0.88). However, using the standard iFR 0.89 threshold, the diagnostic accuracy of iFR was significantly lower in AS compared with CAD (76.3% vs 86.1%, p=0.009). According to ROC analysis, the best iFR cut-off in predicting FFR≤0.8 was lower in AS (0.83, J=0.82) compared with CAD (0.89, J=0.81). Using the ROC derived cut-off of 0.83, the iFR accuracy increased significantly (91.3%, p=0.003) while maintaining an elevated negative predictive value (95.5%). CONCLUSIONS In the presence of severe AS, conventional iFR cut-off had lower diagnostic agreement with FFR classification of coronary lesions compared to stable CAD patients. AS seems to influence iFR cut-off ischemic thresholds and deserves further comparative studies.

Hemodynamic predictors of long term survival in end stage cystic fibrosis

BACKGROUND Pulmonary hypertension (PH) is often found in cystic fibrosis (CF) patients affected by end-stage lung disease but its impact on outcome remains unclear. Pulmonary arterial compliance (PAC) is an important determinant of right ventricle (RV) workload and it is a strong predictor of survival in other forms of PH. The aim of this study is to investigate whether PAC is a predictor of long-term prognosis in a population of CF patients affected by advanced lung disease. METHODS Between 2000 and 2014, 178 patients with CF have been evaluated for lung transplantation in our CF Center. Right heart catheterization (RHC) and follow up data were retrievable and analyzed in 141 of them. PAC was defined as the ratio between stroke volume (SV) and pulse pressure (PP) at heart catheterization. The association of PAC with survival was tested at 4 years and compared to other hemodynamic parameters. RESULTS PH prevalence was 56.4%. Most patients had mild elevation of pulmonary artery pressure (PAP). No difference in mortality was observed in patients with PH compared to patients with normal PAP (HR 0.95: 95% CI 0.49-1.89, p=0.89). At receiver operating characteristic curve (ROC) analysis, the optimal prognostic cut-off point of PAC was 1.95 ml/mmHg. An impaired PAC (≤1.95 ml/mmHg) was a strong independent predictor of long-term mortality (HR 3.44: 95% CI 1.51-7.85: p=0.003). CONCLUSIONS Impaired PAC is associated with poor prognosis in CF patients awaiting lung transplantation. Other traditional hemodynamic parameters add no prognostic information.

Preventive left main and right coronary artery stenting to avoid coronary ostia occlusion in high-risk stentless valve-in-valve transcatheter aortic valve implantation

Transcatheter aortic valve implantation is becoming an attractive and promising alternative to redo surgery for aortic bioprosthetic valves degeneration, especially in high-risk patients. However, valve-in-valve transcatheter aortic valve implantation itself carries some procedural risks and potential challenges that interventionists must be aware of. An accurate preprocedural planning is fundamental for the prevention of potentially fatal complications. This case describes a novel strategy of simultaneous right and left coronary artery stenting preventing bilateral coronary obstruction in a patient with a stentless surgical aortic valve and extremely low origin of the 2 coronary arteries.

Drug eluting balloon for the treatment of patients with coronary artery disease: Current perspectives

Despite the improvement of outcomes after the introduction of bare metal and drug eluting stents for the treatment of CAD, certain type of patients have still an increased risk of stent failure. An alternative is represented by drug-eluting balloons (DEB). This innovation could give potential benefits in particular for the in-stent restenosis (ISR) and the de-novo lesions. In the first setting DEB have shown results superior to those with plain-balloon angioplasty and similar to those with first generation DES. Their performance seems to be more evident in BMS-ISR than in DES-ISR, showing a reliable effectiveness in those cases of recalcitrant ISR or when dual antiplatelet therapy is not indicated. In the context of de-novo lesions the use of DEB as unique strategy results more safe and feasible than a strategy with combined BMS implantation. The results are comparable to DES in lesions limited to small coronary vessels. Other particular scenarios, like bifurcations, acute myocardial infarction and diffuse disease, have been approached with DEB resulting in very heterogeneous outcomes. At present, given the high efficacy of last generation DESs, DEBs should be considered where clinical and angiographic conditions require the avoidance of stent implantation.

First Observation of a "Golden Tube" After Complete Resorption of a Bioresorbable Vascular Scaffold in a Transplanted Patient With Cardiac Allograft Vasculopathy

The promise of complete histological reconstruction of the arterial wall after implantation of a bioresorbable vascular scaffold to treat atherosclerotic segments has challenged the way in which endovascular interventions are conceived. However, the observation of this phenomenon is not yet part of

Long-term follow-up after trans-catheter tricuspid valve-in-valve replacement with balloon–expandable aortic valves

BACKGROUND Transcatheter tricuspid VIV replacement has been proposed as a feasible option for high-risk patients with previous tricuspid valve replacement that undergo valve degeneration causing refractory heart failure. However, little is known about the long-term outcome of patients treated with transcatheter tricuspid VIV. We evaluate the safety of transcatheter tricuspid valve-in-valve (VIV) replacement by using balloon-expandable aortic valve stents and the long-term follow-up. METHODS AND RESULTS From January 2013 to March 2016, 4 patients underwent transcatheter tricuspid VIV in our center using balloon-expandable Edwards Sapien-XT and Sapien-3 valves. In all cases the procedure succeeded with significant improvement of the tricuspid valve area (from 0.98±0.29cm2 to 3.1±0.45cm2, p=0.005), right atrial pressure (from 21±7.78mmHg to 8.5±2.51mmHg, p=0.025) and mean trans-valvular gradient (from 11.5±4mmHg to 3.32±1.28mmHg, p=0.02). Three out of 4 patients presented a follow up longer than 2.5years. At median follow up of 32months (range 9-47months) all patients were alive and presented with NYHA class I-II. Only one patient, who presented impaired right ventricular function at baseline, experienced re-hospitalization during the follow-up time. Echocardiographic assessment at long-term disclosed a well-maintained hemodynamic performance with low trans-valvular gradients and no significant valvular regurgitation in all cases. CONCLUSIONS In our experience, trans-catheter tricuspid VIV demonstrated good long-term results in terms of valve performance and functional class improvement at 32months from intervention.