Odd Bech-Hanssen

Effects of Levosimendan on Left Ventricular Relaxation and Early Filling at Maintained Preload and Afterload Conditions After Aortic Valve Replacement for Aortic Stenosis

Background— We determined the effects of levosimendan, a calcium sensitizer, on left ventricular (LV) diastolic function in patients with LV hypertrophy. Methods and Results— In this prospective, randomized, blinded study, 23 patients received either levosimendan (0.1 and 0.2 &mgr;g · kg−1 · min−1; n=12) or placebo (n=11) after aortic valve replacement for aortic stenosis. The effects on LV performance, dimensions, filling patterns, and isovolumic relaxation time, as well as systemic hemodynamics, were assessed by pulmonary artery thermodilution catheterization and transesophageal 2-dimensional Doppler echocardiography. To circumvent the confounding effects of the levosimendan-induced hemodynamic changes on Doppler echocardiographic indexes of LV early relaxation, heart rate and mean arterial and central venous pressures were kept constant during levosimendan/placebo infusion by atrial pacing, vasopressor, and colloid infusions. In the levosimendan group, dose-dependent increases in cardiac output (28%; P<0.001) and stroke volume (26%; P<0.001) and a decrease in systemic vascular resistance (−22%; P<0.001) were observed. There was a trend for an increase in LV ejection fraction (12%; P=0.058) with levosimendan. There were no significant differences in systolic, diastolic arterial, or LV filling pressures or LV end-diastolic area between the 2 groups. Isovolumic relaxation time decreased (−23%; P<0.001), as did the deceleration slope of early diastolic filling (−45%; P<0.01), whereas peak early diastolic filling velocity (16%, P<0.01) and peak late diastolic filling velocity (15%; P<0.001) increased after levosimendan compared with placebo. Conclusion— Levosimendan, in addition to its inotropic effects, exerts a direct positive lusitropic effect in patients with LV hypertrophy as it shortens isovolumic relaxation time and improves LV filling.

Influence of aortic valve replacement, prosthesis type, and size on functional outcome and ventricular mass in patients with aortic stenosis

OBJECTIVES Two years after surgery for severe aortic stenosis, we prospectively evaluated the influence of aortic valve replacement, as well as valve type (mechanical or stented biologic) and size, on functional status, left ventricular function, and regression of mass. METHODS Patients who received either a mechanical (n = 95) or a biologic valve (n = 42) were studied by echocardiography before the operation and after 2 years. RESULTS The percentage of patients with severe dyspnea decreased from 53% to 13% (P =.001). The cardiac index increased from mean 2.6 L/min per square meter (95% CI: 2.48-2. 72 L/min per square meter) to 3.1 L/min per square meter (95% CI: 2. 94-3.26 L/min per square meter; P =.001). The percentage of the patients with mild-to-moderate diastolic dysfunction decreased from 43% to 18% (P =.001). The left ventricular mass index was reduced by 42.4 g (95% CI: 35-50 g; P =.001). In comparison with biologic valves of the same size, mechanical valves produced a more pronounced reduction in mass index (overall difference 21.7 g; 95% CI: 37.1-6.4 g; P =.007) and a lower mean Doppler gradient (overall difference 4 mm Hg; 95% CI: 2-6 mm Hg; P =.0002). CONCLUSIONS Patients undergoing aortic valve replacement had an improvement in functional status, as well as systolic and diastolic left ventricular function, and a reduction in left ventricular mass index, irrespective of prosthesis size and type. Mechanical valves are somewhat less obstructive than stented bioprosthetic valves of the same size. They are also associated with a concomitantly more pronounced reduction of left ventricular mass.

Gender differences in patients with severe aortic stenosis: impact on preoperative left ventricular geometry and function, as well as early postoperative morbidity and mortality

OBJECTIVE In patients with severe aortic stenosis, we studied the impact of gender on preoperative left ventricular geometry and function, as well as on early postoperative mortality and morbidity. METHODS Prospective Doppler echocardiographic evaluation was performed in 99 female patients and 96 males. RESULTS The patients had severe aortic stenosis and the mean pressure gradients were similar in females and males. Left ventricular diastolic volume adjusted for body surface area (BSA) was larger in males, 55+/-17.4 ml/m2 versus 43+/-13.1 mL/m2 (mean+/-standard deviation; P = 0.0001). The ejection fraction was similar in females (55+/-14%) and males (55+/-13%), and patients of both sexes had significantly lower stroke volume and cardiac index than healthy controls. The relative wall thickness (wall thickness/diastolic diameter ratio) was higher (P = 0.03) in females (0.47+/-0.10) than in males (0.43+/-0.10) Consequently, the diastolic diameter/wall thickness ratio (a substitute for wall tension) was higher (P = 0.02) in males (4.2+/-0.99) than in females (3.9+/-0.80). Compared with survivors, patients who died within 30 days of the operation (n = 17, 11 females) had a smaller body surface area (1.70+/-0.19 vs. 1.82+/-0.19 m2, P = 0.012), smaller left ventricular outflow tract (20.8+/-0.21 vs. 22.0+/-0.22 mm, P = 0.023), higher incidence of abnormal intraventricular flow velocity (33 vs. 8%, P = 0.018) and increased relative wall thickness (0.52+/-0.17 vs. 0.45+/-0.09 P = 0.039). Gender was of no independent importance for early mortality when age and left ventricular outflow tract diameter were accounted for. CONCLUSIONS Cardiac adaptation to aortic stenosis seems to be influenced by gender, males presenting larger left ventricular volumes and higher wall tension. The echocardiographic findings of a narrow left ventricular outflow tract, abnormally increased intraventricular velocity and increased relative wall thickness identified patients with increased risk of early postoperative mortality. However gender had no independent impact on early postoperative outcome.

Survival and Quality of Life After Aortic Root Replacement With Homografts in Acute Endocarditis

BACKGROUND Treatment of prosthetic aortic valve endocarditis and native aortic valve endocarditis with abscess formation is associated with high mortality and morbidity. Aortic root replacement with a freestanding aortic homograft is an attractive alternative. We report outcome and quality of life after homograft replacement for infective endocarditis. METHODS Sixty-two patients with infective prosthetic valve endocarditis (n = 31) or native valve endocarditis with abscess (n = 31), operated with homograft replacement were included. Thirty-day mortality, severe operative complications (dialysis, stroke, pacemaker implantation, myocardial infarction, and prolonged mechanical ventilation), midterm survival, reoperations, and quality of life were assessed after a mean follow-up of 37 ± 11 months. RESULTS Nine patients (15%) died within 30 days and 22 patients (35%) had severe perioperative complications. Preoperative and perioperative variables univariately associated with early mortality were higher (Cleveland Clinic risk score [p = 0.014], extracorporeal circulation time [p = 0.003], prolonged inotropic support [p = 0.03], reoperation for bleeding [p = 0.01], and perioperative myocardial infarction [p < 0.001].) Cumulative survival was 82%, 78%, 75%, and 67% at one, three, five, and ten years, respectively. One patient was reoperated due to recurrence of endocarditis nine months after surgery and one after five years due to homograft failure. Quality of life, as assessed by the 36 item short-form health survey scales for physical and mental health, was not significantly different to an age-matched and gender-matched healthy control group. CONCLUSIONS Severe acute aortic endocarditis treated with homograft replacement is still associated with a substantial early complication rate and mortality. Long-term survival and quality of life are satisfactory in patients surviving the immediate postoperative period.

Reference Doppler Echocardiographic Values for St. Jude Medical, Omnicarbon, and Biocor Prosthetic Valves in the Aortic Position

The objectives of the present investigation were (1) to describe Doppler echocardiographic findings for mechanical and biologic aortic valves at an early stage after operation and later in a stable phase and (2) to study the changes occurring between these investigations. Patients (n = 213) who received a mechanical (St. Jude Medical, Omnicarbon) or a biologic (Biocor) valve were studied by Doppler echocardiography within the first week (baseline, n = 203) and after 2 years (late, n = 172). The comparison of baseline with late investigation (mean +/- SD) showed an increase in systolic blood pressure (137 +/- 18.5 to 154 +/- 20.6 mm Hg, p = 0.0001, n = 112), reduction of heart rate (85 +/- 15.3 to 74 +/- 12.0 beats/min, p = 0.0001, n = 141) and increase in stroke volume (59 +/- 20.6 to 77 +/- 19.8 ml, p = 0.0001, n = 132). Prosthetic Doppler echocardiographic findings demonstrated a reduction in blood flow velocity in the left ventricular outflow tract (VLVOT, 1.10 +/- 0.25 to 0.96 +/- 0.23 m/sec, p = 0.0001, n = 146) reduction in peak velocity (Vmax 2.72 +/- 0.53 to 2.59 +/- 0.54 m/sec, p = 0.02, n = 150), reduction in mean pressure gradient (deltaPmean, 18.4 +/- 7.2 to 16.3 +/- 7.3 mm Hg, p = 0.004) and an increase in velocity index (Vmax/VLVOT, 2.56 +/- 0.62 to 2.67 +/- 0.60, p = 0.003, n = 144). The standard deviations of difference between baseline and late investigation expressed as percentage of mean were 25% for VLVOT, 20% for Vmax, 44% for deltaPmean, and 25% for velocity index. In conclusion, this large reference base provides data that should be useful for the clinician evaluating patients with prosthetic valves early after valve replacement as well as at a later stage. When valve dysfunction is suspected a previous investigation for comparison is helpful, and our data describe the changes that normally may be seen between an early baseline and a late investigation.

Impact of body composition, fat distribution and sustained weight loss on cardiac function in obesity

BACKGROUND Obesity is associated with alterations in left ventricular function varying along with the degree of fatness, but the mechanisms underlying this co-variation are not clear. In a case-control study we examined how sustained weight losses affect cardiac function and report on how body composition and fat distribution relate to the left ventricular performance. METHODS At the 10-year follow-up of the Swedish obese subjects (SOS) study cohort we identified 44 patients with sustained weight losses after bariatric surgery (surgery group) and 44 matched obese control patients who remained weight stable (obese group). We also recruited 44 matched normal weight subjects (lean group). Dual-energy X-ray absorptiometry, computed tomography and echocardiography were performed to evaluate body composition, fat distribution and cardiac function. RESULTS BMI was 42.5 kg/m(2), 31.5 kg/m(2) and 24.4 kg/m(2) for the obese, surgery and lean groups respectively. Increasing degree of obesity was associated with larger left ventricular volumes (p < 0.001), higher cardiac output (p < 0.001), reduced systolic myocardial velocity (p<0.001) and impaired ventricular relaxation (p = 0.015). In multivariate analyses, left ventricular volume, stroke volume and cardiac output primarily associated with lean body mass, whereas blood pressure, heart rate and variables reflecting cardiac dysfunction were more related to total body fat and visceral adiposity. CONCLUSION Obesity is associated with discrete but distinct disturbances in the left ventricular performance appearing to be related to both the total amount of body fat and degree of visceral adiposity. Patients with sustained weight losses display superior left ventricular systolic and diastolic functions as compared with their obese counterparts remaining weight stable.

The Influence of Body Composition, Fat Distribution, and Sustained Weight Loss on Left Ventricular Mass and Geometry in Obesity

Alterations in left ventricular mass and geometry vary along with the degree of obesity, but mechanisms underlying such covariation are not clear. In a case–control study, we examined how body composition and fat distribution relate to left ventricular structure and examine how sustained weight loss affects left ventricular mass and geometry. At the 10‐year follow‐up of the Swedish obese subjects (SOS) study cohort, we identified 44 patients with sustained weight losses after bariatric surgery (surgery group) and 44 matched obese control patients who remained weight stable (obese group). We also recruited 44 matched normal weight subjects (lean group). Dual‐energy X‐ray absorptiometry, computed tomography, and echocardiography were performed to evaluate body composition, fat distribution, and left ventricular structure. BMI was 42.5 kg/m2, 31.5 kg/m2, and 24.4 kg/m2 for the obese, surgery, and lean groups, respectively. Corresponding values for left ventricular mass were 201.4 g, 157.7 g, and 133.9 g (P < 0.001). In multivariate analyses, left ventricular diastolic dimension was predicted by lean body mass (β = 0.03, P < 0.001); left ventricular wall thickness by visceral adipose tissue (β = 0.11, P < 0.001) and systolic blood pressure (β = 0.02, P = 0.019); left ventricular mass by lean body mass (β = 1.23, P < 0.001), total body fat (β = 1.15, P < 0.001) and systolic blood pressure (β = 2.72, P = 0.047); and relative wall thickness by visceral adipose tissue (β = 0.02, P < 0.001). Left ventricular adjustment to body size is dependent on body composition and fat distribution, regardless of blood pressure levels. Obesity is associated with concentric left ventricular remodeling and sustained 10‐year weight loss results in lower cavity size, wall thickness and mass.

Important pressure recovery in patients with aortic stenosis and high Doppler gradients.

Pressure recovery has been described in aortic stenosis and may explain the difference occasionally observed between Doppler- and catheter-measured gradients. A narrow ascending aorta (AA) and moderately severe stenosis favors pressure recovery. The aims of this study were to investigate the degree to which these conditions are present in patients with aortic stenosis and high Doppler gradients and to evaluate the magnitude of pressure recovery. One hundred sixteen patients were examined with Doppler echocardiography before aortic valve replacement. Patients with a maximum gradient >70 mm Hg (n = 81) were included. The diameter of the AA was measured and compared with the diameter in an age- and body size-matched group of normal controls (n = 23). Pressure recovery was estimated from a previously validated equation by measuring the maximum Doppler gradient, the effective orifice area (EOA), and the diameter of the AA. The diameter of the AA was similar for patients (mean 3.0 cm, range 2.1 to 4.1) and normal controls (mean 3.0 cm, range 2.3 to 3.5). The maximum Doppler gradient was 107 mm Hg (range 71 to 170) and the EOA was 0.6 cm(2) (range 0.2 to 1.3). The calculated pressure recovery was 18 mm Hg (range 6 to 37), which gives a net gradient of 89 mm Hg (range 51 to 151). Twenty-three percent had a net gradient <70 mm Hg. A cutoff of EOA/AA diameter at >0.2 cm identified 84% of patients (16 of 19) with a net gradient <70 mm Hg. In conclusion, we found that important pressure recovery can be expected in most patients with aortic stenosis and high Doppler gradients. Pressure recovery may explain why some patients with high Doppler gradients are asymptomatic. Also, pressure recovery is a factor to consider in patients with atypical symptomatology and high Doppler gradients when one must decide on valvular replacement.

Mortality after mitral regurgitation surgery: importance of clinical and echocardiographic variables

OBJECTIVES The management of patients with mitral regurgitation (MR) constitutes a challenge due to its heterogeneity in terms of etiology and possible treatment strategies. In the present study, we sought to describe the importance of preoperative echocardiographic and clinical variables in relation to outcome 5 years after surgical treatment of MR. METHODS The echocardiographic reports (transthoracic) from 298 patients were analyzed and the anatomic lesions were classified into one of three main groups (functional, organic degenerated with hypermobile valve or organic degenerated without hypermobility). 5-year cumulative survival was compared with the expected survival in an age- and gender-matched normal population. Risk functions were determined with a Poisson regression model. RESULTS Operative mortality was 4.4%, with higher mortality in patients with concomitant coronary artery bypass grafting (CABG) (7.6 vs. 2.2%, P=0.03). Survival after 5 years was 65% in patients with concomitant CABG, compared with the expected 86% (P<0.001), 70 vs. 88% (P<0.001) in patients with preoperative NYHA class III/IV, while survival in patients with NYHA class I/II did not differ from the expected (90 vs. 90%, P=0.56). In patients with a hypermobile valve without CABG, postoperative survival did not differ from the expected (91 vs. 89%, P=0.92). The estimated risk ratio for death, repair versus prosthesis, was 0.57 (95% confidence interval 0.32-1.00, P=0.05). CONCLUSIONS The present study shows that it is possible, using transthoracic echocardiography and clinical data, to identify patients with an excellent outcome. The adverse effects of severe symptomatology and replacement compared with repair are demonstrated. The findings encourage early intervention before severe symptoms occur, especially if repair is possible.

Anatomical mismatch of the pulmonary autograft in the aortic root may be the cause of early aortic insufficiency after the Ross procedure

OBJECTIVE Early aortic insufficiency can be a problem after the Ross procedure. Anatomical mismatch and an inexact surgical technique may lead to distortion of the normal pulmonary valve geometry and subsequent incorrect leaflet coaptation and valve insufficiency. In this study, we assessed the efficacy of changing and improving the surgical technique to minimize the early pulmonary autograft valve failure. The modifications and the strategy are discussed. METHODS From January 1995 to February 1999, a total of 77 adults underwent the Ross procedure for aortic valve replacement at Sahlgrenska University Hospital. The operative technique used was full free-standing aortic root replacement with a pulmonary autograft in all cases. In the first 24 cases, the diameter of the pulmonary roots was seldom measured, eye-balling was used to exclude anatomical mismatch due to a dilated aortic root, and only one attempt of correction was made, which failed. In the other 53 cases, the technique was improved by: (1) reducing the aortic anulus diameter in cases with moderate dilatation; (2) excluding cases with severe dilatation of the aortic annulus; (3) adjusting the diameter of the sinotubular junction of the aorta to the diameter of the sinotubular junction of the pulmonary artery; (4). reimplanting the left ostium in the autograft, and (5) changing the proximal anastomosis technique. RESULTS In this study, we had an early aortic incompetence of grade 2 in eight patients among the first 24 patients. In the other 53 patients, postoperative echocardiography at 1 week revealed aortic insufficiency of grade 2 in two patients. CONCLUSIONS Aortic insufficiency after the Ross procedure can be minimized by patient selection, intraoperative correction of anatomical mismatch and improved surgical technique.