Emin Murat Tuzcu

Occult and Frequent Transmission of Atherosclerotic Coronary Disease With Cardiac Transplantation Insights From Intravascular Ultrasound

BACKGROUND Transplant coronary artery disease is a major cause of morbidity and mortality after cardiac transplantation. However, limited data exist regarding the potential contribution of coronary atherosclerosis in the donor heart to cardiac-allograft vasculopathy. METHODS AND RESULTS We performed quantitative coronary angiography and intravascular ultrasound imaging in 50 of 62 consecutive heart-transplant recipients (40 men, 10 women, mean age, 53 +/- 9 years) 4.6 +/- 2.6 weeks after transplantation. The donor population consisted of 30 men and 20 women (mean age, 32 +/- 12 years). Ultrasound imaging visualized all three coronary arteries in 22 patients, two coronary arteries in 23, and one coronary artery in 5. Ultrasound imaging detected coronary atherosclerosis (intimal thickness > or = 0.5 mm) in 28 patients (56%). However, the angiography was abnormal in only 13 patients (26%). The sensitivity and specificity of coronary angiography were 43% and 95%, respectively. With ultrasound, the average atherosclerotic plaque thickness was 1.3 +/- 0.6 mm and the cross-sectional area narrowing was 34 +/- 16%. Atherosclerotic involvement frequently was focal (85%), eccentric (mean eccentricity index, 87 +/- 8), and near arterial bifurcations. Donors of the transplant recipients with coronary atherosclerosis were older than those without atherosclerosis (37 +/- 12 versus 25 +/- 10 years, P = .001). Maximal intimal thickness correlated with donor age (r = .54, P = .0001). Multivariate analysis demonstrated that donor age (P = .0001), male sex of donor (P = .0006), and recipient age (P = .03) were independent predictors of atherosclerosis. CONCLUSIONS Coronary atherosclerosis is frequently but inadvertently transmitted by means of cardiac transplantation from the donor to the recipient. Long-term outcomes of donor-transmitted coronary artery disease will require further evaluation.

Influence of Transcatheter Aortic Valve Replacement Strategy and Valve Design on Stroke After Transcatheter Aortic Valve Replacement : A Meta-Analysis and Systematic Review of Literature

OBJECTIVES The study undertook a systematic review to establish and compare the risk of stroke between the 2 widely used approaches (transfemoral [TF] vs. transapical [TA]) and valve designs (CoreValve, Medtronic, Minneapolis, Minnesota vs. Edwards Valve, Edwards Lifesciences, Irvine, California) for transcatheter aortic valve replacement (TAVR). BACKGROUND There has been a rapid adoption and expansion in the use of TAVR. The technique is however far from perfect and requires further refinement to alleviate safety concerns that include stroke. METHODS All studies reporting on the risk of stroke after TAVR were identified using an electronic search and pooled using established meta-analytical guidelines. RESULTS 25 multicenter registries and 33 single-center studies were included in the analysis. There was no difference in pooled 30-day stroke post-TAVR between the TF and TA approach in multicenter (2.8% [95% confidence interval (CI): 2.4 to 3.4] vs. 2.8% [95% CI: 2.0 to 3.9]) and single-center studies (3.8% [95% CI: 3.1 to 4.6] vs. 3.4% [95% CI: 2.5 to 4.5]). Similarly, there was no difference in pooled 30-day stroke post TAVR between the CoreValve and Edwards Valve in multicenter (2.4% [95% CI: 1.9 to 3.2] vs. 3.0% [95% CI: 2.4 to 3.7]) and single-center studies (3.8% [95% CI: 2.8 to 4.9] vs. 3.2% [95% CI: 2.4 to 4.3]). There was a decline in stroke risk with experience and technological advancement. There was no difference in the outcome of 30-day stroke between TAVR and surgical aortic valve replacement. CONCLUSIONS Our findings suggest that the risk of 30-day stroke after TAVR is similar between the approaches and valve types. There has been a decline in stroke risk after TAVR with improvements in valve technology, patient selection, and operator experience.

Late Stroke: Comparison of Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting in Patients With Multivessel Disease and Unprotected Left Main Disease A Meta-Analysis and Review of Literature

Background and Purpose— Studies have suggested that the early excess risk of stroke in coronary artery bypass grafting (CABG) may be compensated for by a slow but progressive catch-up phenomenon in patients undergoing percutaneous coronary intervention (PCI). We therefore undertook this analysis to compare the temporal stroke risk between PCI and CABG in patients with unprotected left main stenosis and multivessel coronary artery disease. Methods— Studies of PCI versus CABG for unprotected left main stenosis and multivessel disease published between January 1994 (stent era) and July 2013 were identified using an electronic search and reviewed using meta-analytic techniques. Results— We selected 57 reports for the meta-analysis by applying the inclusion and exclusion criteria. The analysis was performed on 80 314 patient records. There was a significantly lower risk of cumulative stroke in patients undergoing PCI with stenting at 1 year (odds ratio [OR], 0.55; 95% confidence interval [CI], 0.42–0.71), 2 years (OR, 0.78; 95% CI, 0.66–0.92), 3 years (OR, 0.79; 95% CI, 0.67–0.92), 4 years (OR, 0.74; 95% CI, 0.56–0.97), and 5 years (OR, 0.79; 95% CI, 0.69–0.91). There was no significant difference in the incidence of stroke because of the small sample size (OR, 0.71; 95% CI, 0.46–1.08) at >5 years between PCI and CABG. Similar results were observed on subgroup analysis (multi-vessel coronary artery disease, unprotected left main, diabetics, and randomized trials) and for stroke within 30 days. Late stroke (stroke >30 days) was similar between the 2 groups. Conclusions— There is a significantly lower risk of stroke within 30 days and cumulative stroke with PCI as compared with CABG up to year 5. There is no late catch up of stroke in the PCI arm. The risk of stroke should be weighed in deciding between revascularization strategies.

Impact of lean six sigma process improvement methodology on cardiac catheterization laboratory efficiency

BACKGROUND Operational inefficiencies are ubiquitous in several healthcare processes. To improve the operational efficiency of our catheterization laboratory (Cath Lab), we implemented a lean six sigma process improvement initiative, starting in June 2010. We aimed to study the impact of lean six sigma implementation on improving the efficiency and the patient throughput in our Cath Lab. METHODS All elective and urgent cardiac catheterization procedures including diagnostic coronary angiography, percutaneous coronary interventions, structural interventions and peripheral interventions performed between June 2009 and December 2012 were included in the study. Performance metrics utilized for analysis included turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start and manual sheath-pulls inside the Cath Lab. RESULTS After implementation of lean six sigma in the Cath Lab, we observed a significant improvement in turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab. The percentage of cases with optimal turn-time increased from 43.6% in 2009 to 56.6% in 2012 (p-trend<0.001). Similarly, the percentage of cases with an aggregate on-time start increased from 41.7% in 2009 to 62.8% in 2012 (p-trend<0.001). In addition, the percentage of manual sheath-pulls performed in the Cath Lab decreased from 60.7% in 2009 to 22.7% in 2012 (p-trend<0.001). CONCLUSIONS The current longitudinal study illustrates the impact of successful implementation of a well-known process improvement initiative, lean six sigma, on improving and sustaining efficiency of our Cath Lab operation. After the successful implementation of this continuous quality improvement initiative, there was a significant improvement in the selected performance metrics namely turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab.

Novel hemodynamic index for assessment of aortic regurgitation after transcatheter aortic valve replacement.

Paravalvular aortic regurgitation (AR) after transcatheter aortic valve replacement (TAVR) has been associated with increased mortality. Precise assessment of the degree of AR within the catheterization laboratory is crucial to take counter measures, but it remains challenging. The aim of this study was to determine whether any modification to AR index can improve its performance.

Simultaneous transapical transcatheter aortic and mitral valve replacement in a high-risk patient with a previous mitral bioprosthesis

Double aortic and mitral valve replacement can now be performedwithacceptableperioperativemorbidityandmortality in experienced hands. However, some patients are denied conventional surgery because of increased perioperative risk. We present a patient with aortic and prosthetic mitral stenosis who was at high risk for conventional surgery that was managed with transcatheter aortic and mitral valve replacement. CLINICAL SUMMARY

Transcatheter aortic valve replacement: History and current indications.

Transcatheter aortic valve replacement is an effective way to treat patients with symptomatic severe aortic valve stenosis who are deemed high risk or inoperable. Current data suggest that the mortality and stroke rates are acceptable compared to surgical aortic valve replacement. There is a possible utility in moderate-risk patients as more data become available.

Paravalvular aortic regurgitation after transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) is a rapidly evolving technology that has been accepted as a treatment option in patients with severe aortic stenosis who are not suitable for or are at high risk for conventional surgery. Randomized trials have shown that TAVR decreases mortality and improves quality of life in patients who are not suitable for conventional surgery and that TAVR is not inferior to standard surgery in operable but high- risk patients. However, TAVR has several important limitations, the most prominent of which is residual paravalvular aortic regurgitation (PAR). The purpose of this review is to present the mechanism, incidence, assessment, and treatment of PAR after TAVR.

Aortic Stenosis Percutaneous Interventions

Transcatheter aortic valve replacement is a disruptive technology for the treatment of severe aortic stenosis. It has allowed for the treatment of high-risk and potentially inoperable aortic stenosis patients. The safety and efficacy of transcatheter aortic valve replacement has been evaluated rigorously in multiple pivotal randomized clinical trials. Advancements in the technology with significant improvement in clinical outcomes and safety of the procedure have allowed for the expansion of indications to lower-risk groups. Future development will focus on patient selection and continued device refinement and technique with further expansion to low-risk patients and other clinical indications.

Transcatheter aortic valve replacement: current state of development

Transcatheter aortic valve replacement is a transformative technology for the treatment of severe aortic stenosis. It has allowed for the treatment of high-risk and inoperable aortic stenosis patients that would previously have not been able to undergo surgical aortic valve replacement. The safety and efficacy of transcatheter aortic valve replacement has been evaluated rigorously in multiple pivotal randomized clinical trials. Advancements in the technology with significant improvement in clinical outcomes and safety of the procedure have allowed for the extension to lower-risk groups. Future development will focus on continued refinement in the device and technique with expansion to low-risk patients and other clinical indications.