The patient-specific aortic silicone model was established based on CTA data. The digital particle image velocimetry (DPIV) test method in the modified ViVitro pulsatile flow system was used to investigate the aortic hemodynamic performance and flow field characteristics before and after transcatheter aortic valve replacement (TAVR). The results showed that the hemodynamic parameters were consistent with the clinical data, which verified the accuracy of the model. From the comparative study of preoperative and postoperative effective orifice area (0.33 cm² and 1.78 cm²), mean pressure difference (58 mmHg and 9 mmHg), percentage of regurgitation (52% and 8%), peak flow velocity (4.60 m/s and 1.81 m/s) and flow field distribution (eccentric jet and uniform jet), the immediate efficacy after TAVR is good. From the perspective of viscous shear stress and Reynolds shear stress, the risk of hemolysis and thrombotic problems was low in preoperative and postoperative patient-specific models. This study provides a set of reliable DPIV testing methods for aortic flow field, and provides biomechanical basis for the immediate and long-term effectiveness of TAVR from the perspective of hemodynamics and flow field characteristics. It has important application value in clinical diagnosis, surgical treatment and long-term evaluation.
Humans ; Transcatheter Aortic Valve Replacement/methods* ; Aortic Valve/surgery* ; Heart Valve Prosthesis ; Hemodynamics ; Aortic Valve Stenosis/diagnosis* ; Treatment Outcome

BACKGROUNDAngina pectoris has been recognized as one of the principal symptoms of aortic valve stenosis (AS), even in patients without significant coronary artery disease (CAD). However, the incidence of angina pectoris and related CAD in such patients is controversial. There is continuing debate as to whether coronary angiography is necessary before aortic valve replacement (AVR) in patients with severe AS. The purpose of this study was to evaluate the incidence and predictors of CAD in patients with severe AS in a Korean population.

METHODSData from all consecutive patients with severe AS undergoing AVR at a major tertiary cardiac and vascular center in Korea were entered in a prospective registry beginning in 1995. Clinical and echocardiographic follow-up data were recorded into the database annually. Significant CAD was defined as one or more major coronary arteries having an estimated narrowing of ≥70% and left main coronary arteries having an estimated narrowing of ≥50% on coronary angiography. We excluded patients with multiple valve disease, significant aortic regurgitation, or prior CAD or valve surgery.

RESULTSTotally 574 patients with severe AS (mean age, (65.9±9.6) years) were enrolled in this study. Significant CAD was found in 61 patients (10.6%). Factors associated with increased likelihood of CAD were age, hypertension, diabetes mellitus, chronic renal failure, carotid disease, and aorta calcification. In Logistic regression analysis, the independent predictor of the presence of CAD was age (P = 0.011). The incidence of CAD increased significantly at 69.2 years of age. Having two risk factors for cardiovascular disease was the most useful cutoff to predict whether a patient was going to have significant CAD.

CONCLUSIONSThere was a low incidence of significant CAD in a population of Korean patients with severe AS. Therefore, coronary angiography before AVR will be considered in patients with multiple risk factors for cardiovascular disease or in patients more than 69 years of age without risk factors for cardiovascular disease.

Aged ; Angina Pectoris ; diagnosis ; epidemiology ; Aortic Valve ; surgery ; Aortic Valve Stenosis ; epidemiology ; surgery ; Coronary Angiography ; Coronary Artery Disease ; diagnosis ; epidemiology ; Echocardiography ; Humans ; Incidence ; Middle Aged

PURPOSE: Transcatheter aortic valve implantation (TAVI) has become an attractive therapeutic strategy for severe aortic stenosis (AS) in elderly patients due to its minimally-invasive nature. Therefore, early results of its clinical outcomes in elderly Korean patients were evaluated. MATERIALS AND METHODS: We compared early clinical outcomes of TAVI, surgical aortic valve replacement (SAVR), and optimal medical therapy (OMT) in patients aged > or =80 years with symptomatic severe AS. Treatment groups were allocated as follows: TAVI (n=10), SAVR (n=14), and OMT (n=42). RESULTS: Baseline clinical characteristics including predicted operative mortality were similar among the three groups. However, patients with New York Heart Association functional class III or IV symptoms and smaller aortic valve area were treated with TAVI or SAVR rather than OMT. In-hospital combined safety endpoints (all-cause mortality, major stroke, peri-procedural myocardial infarction, life-threatening bleeding, major vascular complication, and acute kidney injury) after TAVI or SAVR were significantly lower in the TAVI group than in the SAVR group (10.0% vs. 71.4%, respectively, p=0.005), along with an acceptable rate of symptom improvement and device success. During the follow-up period, the TAVI group showed the lowest rate of 3-month major adverse cardiovascular and cerebrovascular events, a composite of all-cause mortality, myocardial infarction, major stroke, and re-hospitalization (TAVI 0.0% vs. SAVR 50.0% vs. OMT 42.9%, p=0.017). CONCLUSION: Treatment with TAVI was associated with lower event rates compared to SAVR or OMT. Therefore, TAVI may be considered as the first therapeutic strategy in selected patients aged > or =80 years with symptomatic severe AS.
Age Factors ; Aged, 80 and over ; Aortic Valve/*surgery ; Aortic Valve Stenosis/diagnosis/*surgery ; Female ; Humans ; Male ; Prognosis ; Risk Factors ; Treatment Outcome

INTRODUCTIONThe effects of reduction of left ventricular (LV) systemic afterload following aortic valve replacement (AVR) for severe aortic valve stenosis (AS) were investigated, using echocardiography and tissue Doppler imaging (TDI).

METHODSWe compared the preoperative and postoperative echocardiographic assessments of 23 patients with severe AS who had undergone isolated AVR (n = 13) or concomitant AVR with coronary artery bypass grafting (CABG) (n = 10). Conventional echocardiographic evaluations and TDI at the lateral mitral annulus were performed.

RESULTSEchocardiography was performed at a median of 120 (interquartile range: 66-141) days after AVR. There was significant reduction in aortic transvalvular mean pressure gradient after AVR. Although LV dimensions, mass and ejection fraction remained unchanged, LV diastolic and systolic functions improved (as observed on TDI). Early diastolic (E'), late diastolic (A') and systolic (S') mitral annular velocities increased significantly (p < 0.05). There was significant improvement in TDI-derived parameters among the patients who had isolated AVR, while among the patients who had concomitant AVR with CABG, only S' had significant improvement (p = 0.028).

CONCLUSIONTDI was able to detect improvements in LV systolic and diastolic function after AVR for severe AS. There was less improvement in the TDI-derived diastolic parameters among patients who underwent concomitant AVR with CABG than among patients who underwent isolated AVR.

Aged ; Aortic Valve ; surgery ; Aortic Valve Stenosis ; diagnosis ; surgery ; Coronary Artery Bypass ; Diastole ; Echocardiography ; Echocardiography, Doppler ; Female ; Heart Valve Prosthesis ; Humans ; Male ; Middle Aged ; Postoperative Period ; Systole ; Ventricular Function, Left

Implanting a valve that will reduce left ventricular mass is critical in aortic stenosis. Regression of left ventricular hypertrophy in 46 aortic valve replacement (AVR) patients receiving a St. Jude Medical (SJM) valve was assessed by serial electrocardiographic and echocardiographic studies during the preoperative, immediate, and late postoperative periods. The patients were divided into three groups according to valve size; 19 mm group (n=9), 21 mm group (n=20), and 23+mm group (n=17). There was no surgical mortality. The NYHA functional class improved from an average of 2.2+/-0.8 preoperatively to 1.3+/-0.5 post-operatively. Left ventricular muscle mass index (LVMI) regression failed to reach statistical significance in the 19 mm group, whereas in the other two groups a steady decrease in the LVMI occurred with follow up. ECG findings were less remarkable showing insignificant differences in voltage among the three groups (p=0.000). In conclusion, the current data suggest that the 19 mm SJM valve may not result in satisfactory left ventricular muscle mass regression despite adequate function, even in small patients. Therefore, additional procedures to accommodate a larger valve may be warranted in the aortic annulus smaller than 21 mm.
Adult ; Aged ; Aortic Valve/ultrasonography ; Aortic Valve Stenosis/surgery* ; Aortic Valve Stenosis/complications ; Echocardiography ; Electrocardiography ; Female ; Follow-Up Studies ; Heart Valve Prosthesis* ; Human ; Hypertrophy, Left Ventricular/prevention & control* ; Hypertrophy, Left Ventricular/etiology ; Hypertrophy, Left Ventricular/diagnosis ; Male ; Middle Age ; Multivariate Analysis ; Postoperative Period ; Remission Induction ; Risk Factors ; Treatment Outcome

Little is known regarding long-term survival and changes in systolic function following surgery after the occurrence of a severe left ventricular (LV) dysfunction in patients with severe aortic stenosis. Inclusion criteria were an aortic valve area less than 1 cm2 and an LV ejection fraction (EF) less than 35%. Between January 1990 and July 2007, 41 (male: 30) patients were identified. The pre-operative mean EF and mean aortic valve area were 26.7+/-6.1% and 0.54+/-0.2 cm2, respectively. Concomitant coronary artery bypass surgery was performed in 8 patients (19.6%). Immediate post-operative echocardiogram showed to be much improved in LV EF (27.2+/-5.5 vs. 37.4+/-11.3, P<0.001), LV mass index (244.2+/-75.3 vs. 217.5+/-71.6, P=0.006), and diastolic LV internal diameter (62.5+/-9.3 vs. 55.8+/-9.6, P<0.001). Post-operative LV changes were mostly complete by 6 months, and were maintained thereafter. There was one in-hospital mortality (2.4%) and 12 late deaths including one patient diagnosed with malignancy in whom LV function was normal. Multivariate analysis showed pre-operative atrial fibrillation and NYHA FC IV to be significant risk factors for cardiac-related death. Aortic valve replacement in patients with significant aortic stenosis and severe LV dysfunction showed acceptable surgical outcomes. Moreover, LV function improved significantly in many patients.
Adult ; Aged ; Aortic Valve/*surgery ; Aortic Valve Stenosis/complications/*mortality/surgery ; Atrial Fibrillation/diagnosis ; Coronary Artery Bypass/methods ; Coronary Artery Disease/diagnosis ; Echocardiography ; Hospital Mortality ; Humans ; Male ; Middle Aged ; Risk Factors ; Severity of Illness Index ; Treatment Outcome ; Ventricular Dysfunction, Left/complications/*mortality/surgery