Aortic valve calcification is an independent factor of left ventricular hypertrophy in patients on maintenance haemodialysis.

BACKGROUND: Calcification and dysfunction of aortic and mitral valves are frequently found in chronic dialysis patients, but their influence on the development of left ventricular hypertrophy (LVH) is not well defined. METHODS: Conventional echocardiography and Doppler measurement of trans-aortic flow velocity were performed in 135 chronic haemodialysis patients, and left ventricular mass index (LVMI) and trans-valve pressure gradients were calculated. Average values of systolic, diastolic and pulse pressure (PP), interdialytic weight gain, chronic overhydration (difference between mean post-dialysis and dry weights), plasma calcium, phosphate, haemoglobin, and urea reduction ratio over the year preceding this study were obtained in every patient. RESULTS: Aortic valve calcification was present in 105 patients (78%), associated with stenosis in eight (6%); 39 patients (29%) had aortic regurgitation. Mitral annular calcification occurred in 35 (26%) cases and mitral regurgitation in 45 (33%). LVH was observed in 104 patients (77%). Logistic analysis revealed that only aortic valve calcification predicted LVH. LVMI was higher in patients with aortic valve calcification than in those without calcification: (mean+/-SD) 241+/-52 vs 154+/-64 g/m(2), P=0.001. LVMI was not different between patients with normal, calcified, or regurgitating mitral valves. Patients with aortic valve calcification had higher trans-valve peak flow velocities and pressure gradients than those with non-calcified valves: 1.65+/-0.53 vs 1.37+/-0.33 m/s, P=0.01, and 12.1+/-8.9 vs 7.9+/-3.6 mmHg, P=0.01, respectively. The LVMI correlated directly with both variables (r=0.27 and r=0.24, P<0.005). Stepwise linear regression on nine covariates potentially influencing LVMI (age, body mass index, time on dialysis, systolic blood pressure, PP, chronic overhydration, haemoglobin concentration, trans-aortic flow velocity, and urea reduction ratio) showed that LVMI was independently associated with (i) PP, (ii) haemoglobin (inverse correlation), (iii) peak aortic flow velocity, and (iv) chronic overhydration (r=0.502, R(2)=0.252, ANOVA F-ratio=10.19, P<0.0005). CONCLUSION: Our findings show that aortic valve calcification is associated with LVH in chronic haemodialysis patients, probably because valve resistance to ventricular outflow is increased as shown by trans-aortic flow velocities and pressure gradients. The effect on LVMI is independent of PP, anaemia, and overhydration.     

Exercise echocardiography predicts postoperative left ventricular remodeling in aortic regurgitation

Objective. We aimed to investigate if preoperative left ventricular (LV) function assessed by exercise echocardiography could predict late postoperative LV function in aortic regurgitation (AR) patients and to evaluate how LV long-axis function is affected late after aortic valve surgery. Design. A total of 21 male chronic AR patients, aged 49 () years, accepted for surgery were examined preoperatively, 6 months-, and 4 years postoperatively, at rest and during exercise. Besides conventional echocardiographic parameters, the atrioventricular plane displacement (AVPD) by M-mode and peak systolic velocity (s’) in the basal LV by color tissue Doppler were measured. Results. Preoperatively EF_rest and EF_exercise, were 55()% and 54()%, respectively, and ?EF 0()%. LV dimensions and volumes indexed to BSA had decreased at the 6-month follow-up and were stable at late follow-up. s'_rest, s'_exercise, AVPD_rest, and AVPD_exercise were unchanged at both the postoperative examinations (all P ≥ 0.05). Preoperative EF_exercise and AVPD_exercise showed inverse correlation to late postoperative indexed LV enddiastolic volume (r = –0.68, p < 0.004 and r = –0.86, P < 0.001) and indexed LV endsystolic volume (r = –0.68, P = 0.004 and r = –0.81, P < 0.001), while there was no correlation to preoperative EF_rest and AVPD_rest (all r < 0.2). Conclusions. Preoperative exercise echocardiography can detect AR patients with suboptimal LV remodeling late postoperatively.     

Left ventricular mass index reduction early after an isolated aortic valve replacement with St Jude medical 19A-HP

Objectives: It has been reported that the left ventricular mass index (LVMI) for the hypertrophic myocardium is reduced at an early stage following surgery. In this study, those factors affecting the changes in early postoperative LVMI were investigated in cases in which a St. Jude Medical 19A-HP (19HP) mechanical heart valve was used.Methods: We studied 16 consecutive patients with pure aortic stenosis undergoing isolated aortic valve replacement using a 19HP between January 1994 and July 2001. The patients were all female, aged 64±6 years, with a body surface area of 1.44±0.10 m² and preoperative echocardiography at 4.2±3.3 days before and 16.3±10.2 days after operation, and cardiac catheterization within a mean epriod of one month before operation. The correlations between the decrease of LVMI at 16.3±10.2 days after operation and perioperative parameters were determined.Results: There was significant LVMI regression postoperative (15±12%,p=0.01), and only a significant negative correlation between the decrease of LVMI and preoperative left ventricular pressure (LVp) [r=−0.74,p<0.01]. There was, no effective LVMI reduction in the high preoperative LVp group (210 mmHg).Conclusion: It is expected that in the high LVp group, huge wall stress was being applied to the left ventricular muscle immediately before surgery and in the early period after surgery. Preoperative LVp is an important index for determining the surgical timing and safe perioperative management. We recommend early surgical treatment before LVp becomes more than 210 mmHg. Read at the 32nd Annual Meeting of the Japanese Society for Cardiovascular Surgery, Oral session, Osaka, February 14–16, 2002.     

Reverse remodelling after aortic valve replacement for chronic aortic regurgitation

OBJECTIVESThis study aimed to assess the long-term outcomes and investigate the factors related to left ventricular (LV) reverse remodelling after aortic valve replacement (AVR) in patients with chronic aortic regurgitation (AR).METHODSA total of 246 patients who underwent AVR for chronic AR at our institution were included in this retrospective study. Primary end-points included all-cause mortality, cardiac mortality and major adverse cerebral and cardiovascular events. Secondary end-points included cardiac function on echocardiography 1 year after surgery. We explored the predictive factors for reverse remodelling 1 year after surgery.RESULTSThe 10-year survival rate was 86.0%, with no cardiac deaths in 93.8% and no major adverse cerebral and cardiovascular events in 79.9% of patients. Postoperative LV function and symptoms were significantly improved 1 year after surgery, but 34 patients (13.8%) did not recover normal function and structure. A significant negative correlation was found between the incidence of cardiac death and major adverse cerebral and cardiovascular events and reverse remodelling. Multivariate logistic regression identified preoperative LV ejection fraction (P = 0.001, odds ratio = 1.057) and LV end-systolic dimension index (P = 0.038, odds ratio = 0.912) as significant predictive factors of reverse remodelling 1 year after surgery.CONCLUSIONSPreoperative LV ejection fraction and LV end-systolic dimension index were predictive factors for reverse remodelling after surgery, which was associated with late outcomes. Earlier surgery may thus help to restore normal LV function and achieve better late outcomes after AVR for AR.     

Hemodynamics and early clinical performance of the St. Jude Medical Regent mechanical aortic valve

BACKGROUND: The St. Jude Medical Regent valve is the next-generation bileaflet aortic prosthesis, modified from the currently marketed St. Jude Medical mechanical valve to achieve a larger geometric orifice without changing the existing design of the pivot mechanism or blood-contact surface areas. The present study reports the hemodynamic and early clinical results of an ongoing multicenter trial investigating the performance of the Regent valve. METHODS: Between July 1998 and July 2001, 361 patients at 17 centers in North America and Europe underwent implantation of a Regent mechanical aortic valve prosthesis. Clinical status was prospectively recorded, and echocardiography with Doppler was performed at discharge and at 2 months, 6 months, 1 year, and 2 years after operation. RESULTS: Follow-up to date is 300 patient-years (average, 0.8 +/- 0.7 years per patient; range, 0.0 to 2.7 years). There were low rates of clinical adverse events. Mean gradient at 6 months was 9.7 +/- 5.3 mm Hg, 7.6 +/- 5.2 mm Hg, 6.3 +/- 3.7 mm Hg, 5.8 +/- 3.4 mm Hg, and 4.0 +/- 2.6 mm Hg, respectively, for 19-mm, 21-mm, 23-mm, 25-mm, and 27-mm valves; effective orifice area was 1.6 +/- 0.4 cm2, 2.0 +/- 0.7 cm2, 2.2 +/- 0.9 cm2, 2.5 +/- 0.9 cm2, and 3.6 +/- 1.3 cm2, respectively. Indexed effective orifice area was equal to or greater than 1.0 cm2/m2 for all valve sizes. Left ventricular mass index decreased significantly between early postoperative (165.9 +/- 57.1 g/m2) and 6-month follow-up (137.9 +/- 41.0 g/m2; delta = -28.0 +/- 49.1 g/m2; p < 0.0001). CONCLUSIONS: The St. Jude Medical Regent aortic valve has excellent hemodynamics and early clinical results, with rapid and significant left ventricular mass regression. Long-term clinical assessment is ongoing.