Infective Endocarditis Caused by Staphylococcus aureus After Transcatheter Aortic Valve Replacement.

BACKGROUND: Staphylococcus aureus (SA) has been extensively studied as causative microorganism of surgical prosthetic-valve infective endocarditis (IE). However, scarce evidence exists on SA IE after transcatheter aortic valve replacement (TAVR). METHODS: Data were obtained from the Infectious Endocarditis After TAVR International Registry, including patients with definite IE after TAVR from 59 centres in 11 countries. Patients were divided into 2 groups according to microbiologic etiology: non-SA IE vs SA IE. RESULTS: SA IE was identified in 141 patients out of 573 (24.6%), methicillin-sensitive SA in most cases (115/141, 81.6%). Self-expanding valves were more common than balloon-expandable valves in patients presenting with early SA IE. Major bleeding and sepsis complicating TAVR, neurologic symptoms or systemic embolism at admission, and IE with cardiac device involvement (other than the TAVR prosthesis) were associated with SA IE (P < 0.05 for all). Among patients with IE after TAVR, the likelihood of SA IE increased from 19% in the absence of those risk factors to 84.6% if ≥ 3 risk factors were present. In-hospital (47.8% vs 26.9%; P < 0.001) and 2-year (71.5% vs 49.6%; P < 0.001) mortality rates were higher among patients with SA IE vs non-SA IE. Surgery at the time of index SA IE episode was associated with lower mortality at follow-up compared with medical therapy alone (adjusted hazard ratio 0.46, 95% CI 0.22-0.96; P = 0.038). CONCLUSIONS: SA IE represented approximately 25% of IE cases after TAVR and was associated with very high in-hospital and late mortality. The presence of some features determined a higher likelihood of SA IE and could help to orientate early antibiotic regimen selection. Surgery at index SA IE was associated with improved outcomes, and its role should be evaluated in future studies.

Clinical practice guideline for transcatheter versus surgical valve replacement in patients with severe aortic stenosis in Latin America.

In elderly (75 years or older) patients living in Latin America with severe symptomatic aortic stenosis candidates for transfemoral approach, the panel suggests the use of transcatheter aortic valve implant (TAVI) over surgical aortic valve replacement (SAVR). This is a conditional recommendation, based on moderate certainty in the evidence (⨁⨁⨁Ο).This recommendation does not apply to patients in which there is a standard of care, like TAVI for patients at very high risk for cardiac surgery or inoperable patients, or SAVR for non-elderly patients (eg, under 65 years old) at low risk for cardiac surgery. The suggested age threshold of 75 years old is based on judgement of limited available literature and should be used as a guide rather than a determinant threshold.The conditional nature of this recommendation means that the majority of patients in this situation would want a transfemoral TAVI over SAVR, but some may prefer SAVR. For clinicians, this means that they must be familiar with the evidence supporting this recommendation and help each patient to arrive at a management decision integrating a multidisciplinary team discussion (Heart Team), patient's values and preferences through shared decision-making, and available resources. Policymakers will require substantial debate and the involvement of various stakeholders to implement this recommendation.

Stroke Complicating Infective Endocarditis After Transcatheter Aortic Valve Replacement.

BACKGROUND: Stroke is one of the most common and potentially disabling complications of infective endocarditis (IE). However, scarce data exist about stroke complicating IE after transcatheter aortic valve replacement (TAVR). OBJECTIVES: The purpose of this study was to determine the incidence, risk factors, clinical characteristics, management, and outcomes of patients with definite IE after TAVR complicated by stroke during index IE hospitalization. METHODS: Data from the Infectious Endocarditis after TAVR International Registry (including 569 patients who developed definite IE following TAVR from 59 centers in 11 countries) was analyzed. Patients were divided into two groups according to stroke occurrence during IE admission (stroke [S-IE] vs. no stroke [NS-IE]). RESULTS: A total of 57 (10%) patients had a stroke during IE hospitalization, with no differences in causative microorganism between groups. S-IE patients exhibited higher rates of acute renal failure, systemic embolization, and persistent bacteremia (p < 0.05 for all). Previous stroke before IE, residual aortic regurgitation ≥moderate after TAVR, balloon-expandable valves, IE within 30 days after TAVR, and vegetation size >8 mm were associated with a higher risk of stroke during the index IE hospitalization (p < 0.05 for all). Stroke rate in patients with no risk factors was 3.1% and increased up to 60% in the presence of >3 risk factors. S-IE patients had higher rates of in-hospital mortality (54.4% vs. 28.7%; p < 0.001) and overall mortality at 1 year (66.3% vs. 45.6%; p < 0.001). Surgical treatment was not associated with improved outcomes in S-IE patients (in-hospital mortality: 46.2% in surgical vs. 58.1% in no surgical treatment; p = 0.47). CONCLUSIONS: Stroke occurred in 1 of 10 patients with IE post-TAVR. A history of stroke, short time between TAVR and IE, vegetation size, valve prosthesis type, and residual aortic regurgitation determined an increased risk. The occurrence of stroke was associated with increased in-hospital and 1-year mortality rates, and surgical treatment failed to improve clinical outcomes.

Incidence, predictors, and clinical outcomes of coronary obstruction following transcatheter aortic valve replacement for degenerative bioprosthetic surgical valves: insights from the VIVID registry.

Aims: There are limited data on coronary obstruction following transcatheter valve-in-valve (ViV) implantation inside failed aortic bioprostheses. The objectives of this study were to determine the incidence, predictors, and clinical outcomes of coronary obstruction in transcatheter ViV procedures. Methods and results: A total of 1612 aortic procedures from the Valve-in-Valve International Data (VIVID) Registry were evaluated. Data were subject to centralized blinded corelab computed tomography (CT) analysis in a subset of patients. The virtual transcatheter valve to coronary ostium distance (VTC) was determined. A total of 37 patients (2.3%) had clinically evident coronary obstruction. Baseline clinical characteristics in the coronary obstruction patients were similar to controls. Coronary obstruction was more common in stented bioprostheses with externally mounted leaflets or stentless bioprostheses than in stented with internally mounted leaflets bioprostheses (6.1% vs. 3.7% vs. 0.8%, respectively; P < 0.001). CT measurements were obtained in 20 (54%) and 90 (5.4%) of patients with and without coronary obstruction, respectively. VTC distance was shorter in coronary obstruction patients in relation to controls (3.24 ± 2.22 vs. 6.30 ± 2.34, respectively; P < 0.001). Using multivariable analysis, the use of a stentless or stented bioprosthesis with externally mounted leaflets [odds ratio (OR): 7.67; 95% confidence interval (CI): 3.14-18.7; P < 0.001] associated with coronary obstruction for the global population. In a second model with CT data, a shorter VTC distance predicted this complication (OR: 0.22 per 1 mm increase; 95% CI: 0.09-0.51; P < 0.001), with an optimal cut-off level of 4 mm (area under the curve: 0.943; P < 0.001). Coronary obstruction was associated with a high 30-day mortality (52.9% vs. 3.9% in the controls, respectively; P < 0.001). Conclusion: Coronary obstruction following aortic ViV procedures is a life-threatening complication that occurred more frequently in patients with prior stentless or stented bioprostheses with externally mounted leaflets and in those with a short VTC.

Gender-related differences on short- and long-term outcomes of patients undergoing transcatheter aortic valve implantation.

OBJECTIVES: This study aimed to compare gender-related differences in outcomes of patients undergoing TAVI over a long-term follow-up period. BACKGROUND: Transcatheter aortic valve implantation (TAVI) has been considered the standard therapy for patients with inoperable or high-risk symptomatic aortic stenosis. The influence of gender-related differences in outcomes of patients undergoing TAVI is currently on debate. METHODS: From January 2008 to January 2015, 819 patients (49% men) underwent TAVI and were included in a multicenter Brazilian registry. Patients were followed-up and clinical outcomes were evaluated according to the updated Valve Academic Research Consortium-2 criteria. RESULTS: Mean follow-up was 497 ± 478 days. Compared with women, men had a lower rate of major or life-threatening bleeding (12.0% vs. 20.6%; HR = 0.57 [95CI% 0.40-0.81]; P = 0.001), and major vascular complications (6% vs. 11.7%; HR = 0.50 [95CI% 0.31-0.82]; P = 0.004). At 30 days, all-cause mortality was lower in men than in women (6.5% vs. 11.5%; P = 0.013), however, cumulative all-cause mortality was similar between groups (25.9% vs. 29.7%, men and women, respectively, HR = 0.92 [95CI% 0.71-1.19]; P = 0.52) over the entire follow-up period. By adjusted Cox regression model, renal function, diabetes, peripheral artery disease, and chronic obstructive pulmonary disease (COPD) remained independently predictors of all-cause mortality. CONCLUSIONS: In this large-scale study evaluating patients undergoing TAVI, 30-day mortality was higher among women than men driven by significant higher rates of major or life-threatening bleeding and major vascular complications. However, all-cause mortality on long-term follow-up was similar between groups. © 2016 Wiley Periodicals, Inc.

The impact of calcium volume and distribution in aortic root injury related to balloon-expandable transcatheter aortic valve replacement.

BACKGROUND: A detailed assessment of calcium within the aortic root may provide important additional information regarding the risk of aortic root injury during transcatheter heart valve replacement (TAVR). OBJECTIVE: We sought to delineate the effect of calcium volume and distribution on aortic root injury during TAVR. METHODS: Thirty-three patients experiencing aortic root injury during TAVR with a balloon-expandable valve were compared with a control group of 153 consecutive TAVR patients without aortic root injury (as assessed by post-TAVR multidetector CT). Using commercial software to analyze contrast-enhanced pre-TAVR CT scans, calcium volume was determined in 3 regions: (1) the overall left ventricular outflow tract (LVOT), extending 10 mm down from the aortic annulus plane; (2) the upper LVOT, extending 2 mm down from the annulus plane; and (3) the aortic valve region. RESULTS: Calcium volumes in the upper LVOT (median, 29 vs 0 mm(3); P < .0001) and overall LVOT (median, 74 vs 3 mm(3); P = .0001) were higher in patients who experienced aortic root injury compared with the control group. Calcium in the aortic valve region did not differ between groups. Upper LVOT calcium volume was more predictive of aortic root injury than overall LVOT calcium volume (area under receiver operating curve [AUC], 0.78; 95% confidence interval, 0.69-0.86 vs AUC, 0.71; 95% confidence interval, 0.62-0.82; P = .010). Upper LVOT calcium below the noncoronary cusp was significantly more predictive of aortic root injury compared to calcium underneath the right coronary cusp or the left coronary cusp (AUC, 0.81 vs 0.68 vs 0.64). Prosthesis oversizing >20% (likelihood ratio test, P = .028) and redilatation (likelihood ratio test, P = .015) improved prediction of aortic root injury by upper LVOT calcium volume. CONCLUSION: Calcification of the LVOT, especially in the upper LVOT, located below the noncoronary cusp and extending from the annular region, is predictive of aortic root injury during TAVR with a balloon-expandable valve.

Redox processes underlying the vascular repair reaction.

Accumulating evidence indicates that vascular dysfunction in atherosclerosis, hypertension, and diabetes is either caused by or accompanied by oxidative stress in the vessel wall. In particular, the role of redox processes as mediators of vascular repair and contributors to post-angioplasty restenosis is increasingly evident. Yet the pathophysiology of such complex phenomena is still unclear. After vascular injury, activation of enzymes such as NADPH oxidase leads to a marked increase in superoxide generation, proportional to the degree of injury, which rapidly subsides. Such early superoxide production is significantly greater after stent deployment, as compared to balloon injury. Recent data suggest the persistence of low levels of oxidant stress during the vascular repair reaction in neointimal and medial layers. Despite the compensatory increase in expression of iNOS and nNOS, nitric oxide bioavailability is reduced because of increased reaction rates with superoxide, yielding as by-products reactive nitrogen/oxygen species that induce protein nitration. Concurrently, the activity of vascular superoxide dismutases exhibits a sustained decrease following injury. This decreased activity appears to be a key contributor to vasoconstrictive remodeling and a major determinant of the occurrence of nitrative/oxidative stress. Replenishment of superoxide dismutase (SOD), as well as treatment with vitamins C and E or the lipid-lowering drug probucol and its analogs, led to decrease in constrictive remodeling and improved vessel caliber. Better understanding of the redox pathophysiology of vascular repair should help clarify the pathogenesis of many other vascular conditions and may provide novel therapeutic strategies to prevent vascular lumen loss.