Prediction of paroxysmal atrial fibrillation after aortic valve replacement in patients with aortic stenosis: identification of potential risk factors

BACKGROUND AND AIM OF THE STUDY: Paroxysmal atrial fibrillation (AF) is a frequent complication after cardiac surgery. The study aim was to identify preoperative predictors of risk for this condition in patients with aortic stenosis after aortic valve replacement. METHODS: The influence of clinical, echocardiographic and 24 h electrocardiogram (ECG) parameters on episodes of paroxysmal AF after aortic valve replacement (AVR) in 423 patients (156 women, 267 men; mean age 58 +/- 10 years) with aortic stenosis was analyzed. Episodes of postoperative paroxysmal AF were noted in 120 patients (28%). RESULTS: Univariate analyses identified the following variables as risk factors for arrhythmia: age, NYHA functional class, history of preoperative paroxysmal AF, left ventricular mass index, >300 supraventricular beats on 24h ECG before surgery, presence of supraventricular tachycardia (SVT), SVT of >5 beats or with a rate >120 beats/min. Concomitant coronary artery bypass (CABG) grafting and presence of enlarged left atrium had no impact. By multivariate analysis, four variables were identified as independent predictors: age (odds ratio 1.7; 95% CI 1.2-2.1); history of paroxysmal AF (OR 3.2; CI 1.4-7.3); presence of >300 supraventricular beats/24 h (OR 1.9; CI 1.1-3.4); and presence of SVT (OR 2.1; CI 1.3-3.4). Discriminatory analysis revealed that a model comprising these four parameters enabled risk prediction in 68% of patients. CONCLUSION: In patients with isolated aortic stenosis, age, past history of paroxysmal AF episodes, >300 supraventricular beats/24 h and presence of SVT during 24 h before AVR were predictors of postoperative paroxysmal AF episodes. Left atrial diameter and simultaneous CABG during AVR did not influence the likelihood of postoperative paroxysmal AF.     

Myocardial apoptosis predicts postoperative course after aortic valve replacement in patients with severe left ventricular hypertrophy

BACKGROUND AND AIM OF THE STUDY: Myocardial apoptosis has been implicated in heart failure and post-infarct remodeling. In some patients with severe aortic stenosis, delayed valvular replacement is associated with a poor in-hospital outcome. The study aim was to evaluate the impact of cardiomyocyte apoptosis on the postoperative course after aortic valve replacement (AVR) for severe aortic stenosis. METHODS: During elective AVR, myocardial biopsies were obtained from the left ventricle of 11 patients with severe left ventricular hypertrophy (LVH), and the samples analyzed for apoptosis. RESULTS: The mean apoptotic rate was 10.4 +/- 3.7 per thousand. (range: 5-16 per thousand). The apoptotic rate correlated directly with preoperative NYHA functional class, duration of intensive care unit (ICU) stay, number of days of postoperative acute renal insufficiency, and serum level of troponin T at 24 h; the apoptotic rate correlated inversely with cardiac index at 24 h postoperatively. At multivariate analysis, the apoptotic rate and left ventricular mass index were independent predictors of prolonged ICU stay. The apoptotic rate and duration of cardiopulmonary bypass were predictive of the duration of postoperative acute renal insufficiency. CONCLUSION: The study results showed an association between myocardial apoptosis and postoperative outcome in patients with severe LVH submitted for AVR. Non-invasive correlates of apoptosis may be introduced as a means of identifying patients at a higher operative risk, and may help in the evaluation of asymptomatic patients with severe aortic stenosis. Anti-apoptotic strategies before and during surgery would possibly ameliorate the surgical results.     

Aortic valve replacement in patients 70 years and older

BACKGROUND: Aortic valvular disease is the most common valvular lesion among elderly patients. Because of changing demographics, it has become increasingly frequent. Aortic valve replacement (AVR) is the only effective treatment for aortic valvular disease. HYPOTHESIS: This study was undertaken to evaluate the results of AVR in an elderly population. METHODS: Data were retrospectively analyzed in 117 consecutive patients (mean age 73.8 years) who underwent AVR between 1991 and 2002. RESULTS: Pure or predominant severe aortic stenosis was present in 108 patients. Nine patients had severe aortic regurgitation. Before valve replacement, 62.4% of the patients were in New York Heart Association (NYHA) functional class III-IV. A bioprosthesis was implanted in 62.4% of the patients, and 37.6% received a mechanical valve. Concomitant cardiac surgical procedures were performed in 25 patients (coronary artery bypass graft in 22, mitral valve replacement in 3). There were 17 deaths, giving a perioperative mortality rate of 14.5%. Multivariate logistic regression showed that repeat surgery for bleeding, prolonged cardiopulmonary bypass time, postoperative respiratory failure, and postoperative acute renal insufficiency were significant independent predictors of operative mortality. Of the 100 hospital survivors, 78 were followed for a mean of 42.9 months. There were six deaths during follow-up; only two of these were cardiac related. Five-year actuarial survival for all patients and for hospital survivors were 70 and 91.1%, respectively. One year post surgery, all patients were in NYHA functional class I-II. CONCLUSION: In a selected patient population, AVR in the elderly is associated with acceptable mortality and morbidity. The outlook for hospital operative survivors is excellent with improved quality of life and an expected survival normal for this particular age.     

Outcome after valve replacement for severe aortic stenosis associated with reduced left ventricular ejection fraction

BACKGROUND AND AIM OF THE STUDY: Because valve replacement for aortic stenosis (AS) remains a difficult surgical challenge in the presence of left ventricular dysfunction, the immediate and long-term outcomes, and evolution of left ventricular ejection fraction (LVEF) in this setting, were analyzed. METHODS: Forty-three consecutive patients with severe AS (valve area < or =1 cm2) and reduced LVEF (< or =40%) who underwent valve replacement surgery at the authors' institution between April 1998 and December 2003 and were studied retrospectively. RESULTS: Preoperative characteristics included: LVEF 33 +/- 6%, mean transaortic pressure gradient 46 +/- 13 mmHg, and aortic valve area 0.58 +/- 0.15 cm2. Concomitant coronary artery bypass grafting was performed in 15 patients (35%). Perioperative (30-day) mortality was 2.3%, with 39.5% morbidity. During a mean follow up of 33.4 +/- 17.6 months, eight patients died. The Kaplan-Meier estimate of five-year survival was 75.3%. Postoperatively, none of the survivors remained in NYHA functional classes III-IV. The postoperative LVEF assessed in 81.8% of survivors had improved. Multivariate analysis associated improved LVEF with a higher preoperative mean transaortic pressure gradient (p = 0.0009) and a higher preoperative LVEF (p = 0.02). CONCLUSION: Patients with severe AS and reduced LVEF can undergo valve replacement with low perioperative mortality and moderate postoperative morbidity. Good long-term survival with good NYHA functional status and improved LVEF can be obtained.     

The evaluation of the left ventricle function in patients with aortic stenosis and severe heart failure after surgical treatment of valvular heart disease

Surgical treatment of aortic stenosis in patients (pts) with severe heart failure represents high-risk procedure. The aim of this study was to identify prognostic factors and assess the late outcome after aortic valve replacement (AVR) in patients with isolated aortic stenosis and left ventricle ejection fraction (EF) < or = 40%. The study group consisted of 37 pts 25 (67%) men and 12 (33%) women, aged 57 +/- 12 yrs. Mean follow-up period was 18 +/- 17 months (range 6 to 72 months). Before AVR and within follow-up period clinical assessment was based on NYHA classes and echocardiographic study to evaluate left ventricle function. Early mortality rate was 8.3%, late mortality was 5.8%. EF significantly improved from 27 +/- 7% to 59 +/- 15% (p < 0.001) after AVR. It was accompanied by clinical improvement. Left ventricle function improvement did not depend on age, sex of patients, concomitant revascularization and preoperative maximum transaortic gradient. Significant correlation (r = -0.4, p = 0.02) between preoperative left ventricle end-diastolic diameter and postoperative EF improvement was noted.     

Left ventricular remodeling after aortic valve replacement]

The aim of the study was the assessment of left ventricular (LV) systolic function and left ventricular mass following aortic valve replacement (AVR) due to aortic valve stenosis as well as the influence of regression of LV hypertrophy in patients with normal and impaired LV systolic function prior to surgery. 74 patients with severe aortic valve stenosis (29 female, 45 male, mean age 66 +/- 18 years) were divided into 2 groups according to LV ejection fraction (EF): Group 1 with EF > 50% (n = 40); Group 2 with EF < or = 50% (n = 34). Furthermore, patients were differentiated into a group A without (n = 53) and a group B with aortic regurgitation (< or = II degrees, n = 21). All patients were examined by transthoracic echocardiography before and 1 month after surgery. There was a significant decrease of LV enddiastolic and endsystolic volume indices following AVR in group 2 and group B. Patients with preoperatively lower EF (group 2) showed an increase in LV ejection fraction from 39 +/- 10% before AVR to 47 +/- 11% after AVR (p < 0.001), whereas patients with preoperative normal EF (group 1) showed a significant decrease in EF (from 62 +/- 8% to 57 +/- 10%, p < 0.05). Also patients with combined aortic valve disease before AVR had an increase of EF after surgery (from 45 +/- 14% to 56 +/- 14%, p < 0.03). There were significant decreases of interventricular septum thickness and LV posterior wall thickness in group 1 and group A, whereas a significant decrease of LV enddiastolic diameter index was noted only in group B. Improvement of the NYHA functional class could be demonstrated in group 2 from 2.8 +/- 0.7 before to 2.2 +/- 0.6 after AVR, as well as in group B from 2.9 +/- 0.7 before to 1.9 +/- 0.7 after surgery. In conclusion, patients with impaired LV function or combined aortic valve disease showed a significant improvement of left ventricular systolic function after AVR, while patients with normal LV function presented a slight decrease of EF. There was a significant regression of left ventricular muscle mass in all groups independent of the left ventricular functional status.     

Pre- and postoperative left ventricular contractile function in patients with aortic valve disease.

In 43 patients left ventricular micromanometry and cineangiography were performed preoperatively and and 20 months after aortic valve replacement. A score of left ventricular functional impairment, derived from 5 to 8 haemodynamic variables, was calculated as: number of pathological indices x 100/total number of determined indices. Preoperatively the score of left ventricular functional impairment amounted to 35 per cent in group 1 (aortic stenosis: n = 19), to 61 per cent in group 2 (combined lesion:n = 15) (P less than 0.05), and to 87 per cent in group 3 (aortic regurgitation: n = 9) (P less than 0.001). In contrast, the functional classification according to the NYHA showed similar impairment in the 3 groups. Postoperatively the score of left ventricular functional impairment decreased significantly in all 3 groups to 10, 16, and 27 per cent, respectively, but the score of group 3 remained raised (P less than 0.05) as compared with that of group 1. The patients with residual left ventricular dysfunction had a higher preoperative left ventricular muscle mass than the patients with normal or near normal postoperative left ventricular function. It is concluded that (1) at similar functional impairment according to the NYHA classification left ventricular contractile function is more severely impaired in aortic regurgitation and in aortic regurgitation + aortic stenosis than in aortic stenosis alone, (2) left ventricular function improves significantly after valve replacement in all three forms of aortic valve disease, (3) residual functional impairment is greater in aortic regurgitation than in aortic stenosis or aortic stenosis + aortic regurgitation, and (4) persistent postoperative left ventricular functional impairment is found in the patients with severe preoperative hypertrophy.     

Severe pulmonary hypertension in patients with severe aortic valve stenosis: clinical profile and prognostic implications

OBJECTIVES: We analyzed the clinical characteristics and outcomes of 47 patients with severe pulmonary hypertension (PHT) and severe aortic valve stenosis (AS) from 1987 to 1999. BACKGROUND: The prognostic implications of severe pulmonary hypertension in patients with severe AS are poorly understood. METHODS: The mean age of patients was 78 years (range 47 to 91 years), and 37 patients (79%) were in New York Heart Association (NYHA) functional class III or IV. Aortic valve replacement (AVR) was performed in 37 patients (79%) and 10 patients (21%) were treated conservatively. RESULTS: In the group that had AVR, there were six perioperative deaths (16%) and nine late deaths, resulting in a total mortality of 32%. In the conservatively treated group, there were eight deaths (80%) on follow-up. Severe PHT was an independent predictor of perioperative mortality. However, perioperative mortality was independent of the severity of left ventricular systolic dysfunction or concomitant coronary artery bypass grafting. Aortic valve replacement was associated with significant improvement in left ventricular ejection fraction, the severity of PHT and NYHA functional class. The difference between long-term survival of the operative survivors and the expected survival from life tables was not statistically significant. CONCLUSIONS: The prognosis for patients with AS and severe PHT treated conservatively without AVR is dismal. Although AVR is associated with higher than usual mortality, the potential benefits outweigh the risk of surgery.     

The effect of aortic valve replacement on left ventricular mass assessed by echocardiography.

AIMS: The aim of the study was to investigate whether aortic valve replacement (AVR) has different effects on the left ventricular mass (LVM) in patients with different types of aortic valve disease, i.e. aortic stenosis (AS), aortic regurgitation (AR), or combined disease. METHODS AND RESULTS: We studied 100 patients with AS; (n=57), AR; (n=22), and combined disease; (n=21). Each patient was evaluated before and up to 8.7 years (mean follow-up period 1.42 +/- 1.65 years) after operation by transthoracic echocardiography. LVM was calculated based on echocardiographic parameters. Following AVR, the LVM for the entire group decreased from 373 +/- 145 g to 280 +/- 102 g (P=0.0001). The AS subgroup lost 13.7 +/- 30.7% from the preoperative LVM, compared to 28.8 +/- 24.8% in the AR subgroup (P<0.05) and 23.1 +/- 33.1% in the combined subgroup. The preoperative LVM was higher among patients with AR vs. AS patients (501 +/- 173 g vs. 319 +/- 100 g respectively, P<0.05). The decrease in LVM was significantly higher in patients with preoperative AR compared to AS patients (165 +/- 150 g vs. 58 +/- 96 g, respectively, P<0.05). However, the postoperative LVM remained higher among the former. The only preoperative parameter (of the LVM formula) that was different between AR and AS patients was the left ventricular end diastolic diameter (68 +/- 11 mm vs. 51 +/- 7 mm, respectively, P<0.05). No significant differences were found in wall thickness among the groups studied. Univariate analysis showed that gender (male), type of aortic valve disease (AR vs. AS), and larger prosthetic valve diameter correlated significantly with greater decrease in postoperative LVM. In multivariate analysis comparing the above variables between AS and AR subgroups, only the patient's gender (i.e. male) was identified as an independent predictor of LVM regression. CONCLUSION: Patients with AR have a greater decline in LVM compared with patients with AS following AVR. The postoperative decline in LVM is higher among males and those with larger prosthetic valve diameter.     

Risk factors for congestive heart failure after aortic valve replacement with a Carpentier-Edwards pericardial prosthesis in the elderly

BACKGROUND AND AIM OF THE STUDY: Congestive heart failure (CHF) after aortic valve replacement (AVR) is an important cause of morbidity. The study aim was to identify preoperative risk factors for CHF. METHODS: A total of 500 consecutive patients (271 males, 229 females; median age 73 years; range: 71-77 years) was investigated retrospectively. The AVR was performed using a Carpentier-Edwards pericardial valve, and a total of 348 additional procedures (313 coronary artery bypass grafts; CABG) was carried out. The outcome studied was CHF, during both hospital stay and long-term follow up. Univariate and multivariate statistical analyses were used to investigate 15 risk factors. RESULTS: During the hospital stay, 13 patients developed CHF, with four fatalities. Significant risk factors for CHF included urgent operation (p = 0.031), preoperative atrial fibrillation (AF) (p = 0.031) and NYHA functional class IV (p = 0.05). A logistic regression analysis revealed need for urgent operation (p = 0.034) as the sole factor. During long-term follow up, 43 patients developed CHF, with seven fatalities. Univariate analysis identified seven risk factors with significant effect: valve size <19 mm (p = 0.004), preoperative conduction defects (p = 0.007), chronic postoperative AF (p = 0.013), cross-clamp time >75 min (p = 0.032), NYHA class IV (p = 0.041), coronary artery disease (CAD) (p = 0.043) and additional CABG (p = 0.050). Multivariate analysis identified three risk factors: preoperative conduction defects (p = 0.004), postoperative AF (p = 0.005) and CAD (p = 0.037) CONCLUSION: Morbidity due to CHF after AVR could be minimized with correct treatment of AF and of conduction defects. Patient age, valve size, cross-clamp time and preoperative severity or symptoms were not independent risk factors. Moreover, small native aortic valve rings should not necessarily be enlarged, the cross-clamp time should be kept to a minimum, and surgery should not be delayed when symptoms have developed.     

Left ventricular remodeling early after aortic valve replacement: differential effects on diastolic function in aortic valve stenosis and aortic regurgitation

OBJECTIVES: The aim of this study was to evaluate the effect of aortic valve replacement (AVR) on left ventricular (LV) function and LV remodeling, comparing patients with aortic valve stenosis to patients with aortic regurgitation. BACKGROUND: Aortic valve disease is associated with eccentric or concentric LV hypertrophy and changes in LV function. The relationship between LV geometry and LV function and the effect of LV remodeling after AVR on diastolic filling, in patients with aortic valve stenosis compared with aortic regurgitation, are largely unknown.Nineteen patients with aortic valve disease (12 aortic valve stenosis, 7 aortic regurgitation) were studied using magnetic resonance imaging to assess LV geometry and LV function before and 9 +/- 3 months after AVR. Ten age-matched healthy males served as control subjects. RESULTS: Before AVR, the ratio between left ventricular mass index (LVMI) and left ventricular end-diastolic volume index (LVEDVI) was only increased in patients with aortic valve stenosis (1.37 +/- 0.16 g/ml) compared with control subjects (0.93 +/- 0.08 g/ml, p < 0.05). After AVR, LVMI/LVEDVI decreased significantly in aortic valve stenosis (to 1.15 +/- 0.14 g/ml, p < 0.0001), but increased significantly in aortic regurgitation (1.02 +/- 0.20 g/ml to 1.44 +/- 0.27 g/ml, p < 0.0001). Before AVR, diastolic filling was impaired in both aortic valve stenosis and aortic regurgitation. Early after AVR, diastolic filling improved in patients with aortic valve stenosis, whereas patients with aortic regurgitation showed a deterioration in diastolic filling. CONCLUSIONS: Early after AVR, patients with aortic valve stenosis show a decrease in both LVMI and LVMI/LVEDVI and an improvement in diastolic filling, whereas in patients with aortic regurgitation, LVMI decreases less rapidly than LVEDVI, causing concentric remodeling of the LV, most likely explaining the observed deterioration of diastolic filling in these patients.     

The effect of aortic valve replacement on N-terminal natriuretic propeptides in patients with aortic stenosis

BACKGROUND: Increased plasma concentrations of natriuretic peptides have been demonstrated to be associated with increased intracardiac pressure and left ventricular (LV) hypertrophy. After aortic valve replacement (AVR) in aortic stenosis patients, there is a relief of the left outflow obstruction with a substantial hemodynamic improvement. This is followed by a gradual regression of the LV hypertrophy. HYPOTHESIS: After AVR, reduction in LV filling pressure is expected to occur rapidly, while regression of LV hypertrophy will take place over a longer time period. On this basis we hypothesized that the plasma levels of N-terminal proatrial natriuretic peptide (NT-proANP) would be reduced early in the postoperative period, while N-terminal probrain natriuretic peptide (NT-proBNP), through its closer reflection of LV hypertrophy, would be sustained for a longer period. METHODS: Two groups of patients with aortic stenosis undergoing AVR were followed for 4 and 12 months, respectively. Plasma concentrations of NT-proANP and NT-proBNP were measured before and after AVR and related to preoperative findings and changes in the aortic valve area index. RESULTS: Before AVR, the patients had significantly increased plasma levels of NT-proANP and NT-proBNP. After AVR, NT- proANP was decreased at 4 and 12 months but remained elevated compared with controls. N-terminal-proBNP tended to decrease, but did not change significantly. When the patients were followed for 12 months, only those with elevated preoperative pulmonary capillary wedge pressure had decreased peptide levels (NT-proANP: p = 0.017, NT-proBNP: p = 0.058). There was no regression of LV hypertrophy. The patients with the largest postoperative valve area index [1.27 (1.10-1.55) cm2/m2] had the largest reduction of NT-proBNP (47%). Those with the smallest valve area index [0.67 (0.54-0.73) cm2/m2] had no decrease in NT-proBNP. CONCLUSIONS: Our study suggests that a reduction in left atrial pressure is the main factor causing the change of NT-proANP level after AVR. A small prosthetic valve orifice area with a high aortic valve gradient might prevent regression of LV hypertrophy, thus representing a stimulus for increased cardiac secretion of NT-proBNP.     

Aortic valve replacement in septuagenarians

To evaluate the risk factors of aortic valve replacement (AVR) in the elderly, 35 patients over the age of 70 who had undergone this procedure were reviewed. Twenty-four patients had isolated AVR, three had double valve replacement, seven had a combined procedure of AVR and aortocoronary bypass, and one had AVR and open mitral commissurotomy. There were 27 elective and eight emergency operations. Nineteen patients were in the New York Heart Association (NYHA) Class III, and 16 patients were in NYHA Class IV preoperatively. Hospital mortality was 7.4% (two cases) in the elective group, and 337.5% (three cases) in the emergency group. The major risk factors were found to be the urgency of operation and left ventricular failure associated with severe pulmonary hypertension. There was no postoperative mortality among the seven patients who underwent the combined procedures of AVR and aortocoronary bypass. Follow-up of survivors revealed that 90% returned to NYHA Class I or II, and have an improved lifestyle. Our data suggest that elective AVR is a safe beneficial operation in septuagenarians. Emergency surgery and severe left ventricular failure contribute to high mortality; therefore, AVR should be performed in septuagenarians as early as indicated.     

Re-do aortic valve replacement: does a previous homograft influence the operative outcome?

BACKGROUND AND AIM OF THE STUDY: Late reoperation for failed aortic homograft is widely regarded as a high-risk procedure. A review is presented of the authors' experience of redo-aortic valve replacement (re-do AVR) examining factors which affect, and whether a previous aortic homograft replacement influences, operative outcome. METHODS: A retrospective review was conducted of consecutive re-do AVR performed at the authors' institution between 1998 and 2002. RESULTS: During the study period, 178 patients (125 males, 53 females; mean age 52.4 years; range: 16-85 years) underwent re-do AVR. The group included first-time (72%), second-time (20%), and more than third-time re-do AVR (8%). Forty-six patients (26%) received a homograft (group I), and 132 (74%) a stented biological/mechanical valve (group II). The two groups were matched for baseline clinical characteristics and operative variables. The type of explanted valve, and preoperative and operative variables, were analyzed using univariate and multivariate models. Primary outcome was defined as 30-day mortality, and secondary outcome as postoperative complications. The overall 30-day mortality was 12.3%, but was much lower (4.5%) for elective isolated and multiple re-do AVR. Univariate analysis showed significant predictors of 30-day mortality to be: age >65 years (p = 0.02); renal dysfunction (p = 0.005); preoperative unstable status (p = 0.03); preoperative NYHA class III/IV dyspnea (p = 0.02); non-elective operation (p = 0.01); preoperative arrhythmia (p = 0.005); history of chronic obstructive pulmonary disease (COPD) (p = 0.002); preoperative cardiogenic shock (p = 0.03); impaired left ventricular ejection fraction (LVEF) <50% (p = 0.04); and other valvular procedure(s) performed simultaneously (p = 0.01). In a multivariate analysis, the only significant predictors of 30-day mortality were impaired LVEF (p = 0.03) and a history of COPD (p = 0.007). Group I patients had a significantly shorter mean hospital stay (10.2+/-5.9 versus 14.1+/-12.5 days; p = 0.009), but there were no significant differences between groups in terms of postoperative complications. CONCLUSION: A previous aortic homograft replacement was not associated with an increased operative risk at the time of re-do AVR. A history was COPD was an important predictor of 30-day mortality, and this finding requires further investigation.     

Frailty after aortic valve replacement (AVR) in octogenarians

In order to analyze the quality of life (QoL) or frailty after AVR for octogenarians, we studied 84 patients older than 80 years who underwent aortic valve replacement alone or in combination with coronary artery bypass, between April 1998 and December 2001. Follow-up was performed in May 2002 with a telephonic interview to evaluate the self-rated QoL, health, and three frailty markers: falls, activity of daily living (ADL) and mood disorder. In-hospital mortality was 16.7%. Fourteen deaths occurred during the follow-up: survival estimates were 85.5% at 1 year and 68.6% at 3 years. Forty-one patients (73.2%) were in New York Heart Association (NYHA) classes I-II for dyspnea and 42 patients (75.0%) were free of angina. Fifty-one patients (91.1%) lived in their own homes. Forty-eight (85.7%) had at least one frailty marker: falls (26.8%), loss of autonomy for ADL (27.0%) or suspected depression (20.2%). All frailty markers were associated with self-rated QoL but not with self-rated health. AVR for octogenarians is associated with good outcome but this population is frail and further studies should assess the usefulness of pre- and postoperative geriatric approach.     

Changes in left ventricular function and mass during serial investigations after valve replacement for aortic stenosis

BACKGROUND AND AIM OF THE STUDY: The potential for left ventricular hypertrophy regression and associated functional improvements may well be the underlying mechanism of results in general after valve replacement for aortic stenosis. The study aim was to investigate preoperative predictors and the time course of such ventricular changes. METHODS: Forty-six patients (mean age 61 years; range: 24-82 years) with aortic stenosis were prospectively followed with serial investigations (Doppler echocardiography, radionuclide ventriculography) at eight days (n = 43), three months (n = 42) and 18 months (n = 39) after valve replacement with a mechanical valve (19-29 mm). The postoperative course of left ventricular ejection fraction (EF), fast filling fraction, mass index and end-diastolic volume index (EDVi) was analyzed in an independent increments statistical model for repeated measurements. RESULTS: EF rose marginally, from 59+/-15% preoperatively to 64+/-16% (p <0.05) at 18 months, independently related to preoperative EF (p = 0.0001) and fast filling fraction (p = 0.0001). Changes in fast filling fraction were similarly predicted by the preoperative starting point (p = 0.003) and by preoperative left ventricular systolic radius:wall thickness ratio (p = 0.0002) with an inverse relation (the larger the chamber and the poorer its contractility, the lower the postoperative fast filling fraction). Mass index was independently related to the time point of postoperative measurement, indicating continuing regression of hypertrophy, from 200+/-66 g/m2 preoperatively to 148+/-49 g/m2 at 18 months (p <0.0001), when only 18% of the patients had normal mass index. Mass index was also independently related to preoperative left ventricular end-systolic dimension index (p = 0.0008) with a constant influence, and systolic wall stress (p = 0.0009) which was modified by time: the influence of wall stress was significant at eight days, weak at three months, and pronounced at 18 months. Left ventricular EDVi after surgery was inversely related to preoperative EF modified by time. Associated coronary artery disease, size of the prosthetic valve, and peak gradient across the valve (mean 15 mmHg; range: 7-26 mmHg at 18 months) did not influence any of the four target variables. CONCLUSION: We conclude that left ventricular response to valve replacement for aortic stenosis is predictable. A significant reduction in hypertrophy occurs during the first 18 postoperative months, but to a normal ventricular mass in only a minority of patients. Insufficient regression of hypertrophy was related to indices of irreversible myocardial disease, which also prevented functional ventricular improvement despite successful valve replacement and a hemodynamically well functioning valve.     

EuroSCORE predicts mid-term outcome after combined valve and coronary bypass surgery

BACKGROUND AND AIM OF THE STUDY: EuroSCORE is widely used to assess operative risk. Combined cardiac procedures carry increased perioperative mortality, but the influence of preoperative factors on mid-term outcome is not well known for these patients. The study aim was to determine if EuroSCORE risk influences mid-term survival after combined coronary artery bypass grafting (CABG) and valve surgery. METHODS: Follow up (mean 23.7 months) was obtained in 258 consecutive hospital survivors (148 males, 110 females; median age 72.29 years; mean EuroSCORE 7 points) operated on between January 1998 and March 2001. CABG + aortic valve replacement (AVR) was performed in 171 patients, CABG + mitral surgery in 72, and CABG + double valve surgery in 15. Kaplan-Meier estimates were calculated for survival and combined freedom from death and NYHA class III/IV. The Cox regression model was applied to prove the influence of EuroSCORE risk and a number of preoperative and operative variables on mid-term outcome. RESULTS: Thirty patients (11.63%) died during follow up, and 34 (13.17%) were in NYHA class III/IV. Freedom from death and NYHA class III/IV was 89.3%, 74.7% and 55.2% at 12, 24 and 36 months, respectively. The significant predictor for combined death and NYHA class III/IV was EuroSCORE risk (p = 0.0004). In the subgroup of patients with CABG + mitral valve surgery, age was identified as a significant risk factor for death (p = 0.0346), whereas in the subgroup of patients with CABG + AVR EuroSCORE was detected as significant risk factor for combined death and NYHA class III/IV. CONCLUSION: EuroSCORE is an important predictor for poor mid-term outcome after combined CABG and valve surgery.     

Aortic valve replacement in childhood: Evaluation of left ventricular function by electrocardiography,echocardiography and graded exercise testing

Preoperative and postoperative left ventricular (LV) performance was evaluated noninvasively in 15 children who survived aortic valve replacement (AVR). The noninvasive evaluation included electrocardiography, M-mode echocardiography, and graded exercise testing. Clinically, there was dramatic improvement postoperatively: All but 2 patients were asymptomatic. No conduction defects or arrhythmias were detected preoperatively; however, in the late postoperative period there was a variety of intraventricular conduction abnormalities, myocardial infarctions, and ventricular or supraventricular arrhythmias. On M-mode echocardiography, children with aortic stenosis continued to have increased LV mass postoperatively. Shortening fraction and left-sided systolic time intervals returned to normal. The children with aortic regurgitation also had persistently abnormal LV mass on echocardiography postoperatively. Exercise data indicated no improvement in working capacity after AVR. Also, 9 children (63%) continued to have ST-segment depression with maximal exercise. These data indicate that AVR does not result in a return to normal of myocardial performance in children with severe aortic valve disease.     

Is the clinical course of non-rheumatic aortic regurgitation the same as that of rheumatic aortic regurgitation?

To determine whether non-rheumatic (NR) aortic regurgitation (AR) has the same clinical and postoperative courses as rheumatic (R) AR, we performed a retrospective study using pre- and postoperative M-mode echocardiograms in 23 patients who underwent aortic valve replacement (AVR) under myocardial protection with hypothermic cardioplegia. The etiology of AR was diagnosed by two-dimensional echocardiography. The NR-AR group consisted of nine patients including four with aortic valve prolapse (AP) and five with bicuspid valve (BV), and the R-AR group included 14 patients. Patients with preoperative end-diastolic dimensions (EDD) of less than 6.0 cm were excluded from this study. The indication for AVR was NYHA functional class III or severer. The severity of preoperative NYHA functional class was similar among these three groups. During the 18-month follow-up period (range 2-32 months), there were no post-operative deaths nor congestive heart failure. Ages at surgery ranged from 17 to 54 years; 10 (71%) of 14 patients with R-AR were 40 years old or older, while seven (78%) of nine with NR-AR were under 39 years old (p less than 0.05). The pre-operative left ventricular end-diastolic pressure (LVEDP) in patients with BV-AR was highest among these three groups (R-AR: 14.5 +/- 3.9 mmHg, AP-AR: 9.5 +/- 4.1 mmHg, BV-AR: 22.0 +/- 2.7 mmHg, p less than 0.05). There was no significant difference in pre-operative M-mode echocardiographic results, except for the end-systolic dimension (ESD) between R-AR (5.20 +/- 0.55 cm) and BV-AR (4.78 +/- 0.18 cm) (p less than 0.05). The EDD one month after AVR was still abnormal (greater than or equal to 5.4 cm) in seven of the 14 patients with R-AR, and three of the four patients with AP-AR but none of the patients with BV-ARs (p less than 0.05 vs AP-AR). All patients with pre-operative ESD of less than 5.2 cm had normal EDD one month after AVR. In conclusion, the clinical course of NR-AR is different from that of R-AR. Furthermore, AP-AR regresses more differently after AVR than does BV-AR. Therefore, it is important to consider the etiology of chronic AR in determining the timing of surgery.     

Is routine use of stentless aortic prostheses justified in an elderly (aged > or =75 years) population?

BACKGROUND AND AIM OF THE STUDY: Stentless prostheses in the aortic position produce a superior hemodynamic profile in comparison to that with stented valves. To determine whether routine use of stentless valves in an elderly population is justified, a 10-year retrospective review was performed of a consecutive series of patients aged > or =75 years undergoing stentless aortic valve replacement (AVR). METHODS: Demographic, operative and mortality data were obtained retrospectively. Survivors were interviewed by telephone according to a defined protocol. Univariate and multivariate analysis was used to identify independent predictors of 30-day and overall medium-term mortality. Definitions and analyses were in accordance with joint STS/AATS guidelines. RESULTS: A total of 103 patients (57 males, 46 females; mean age 79.8 years; range: 75-91 years) underwent AVR with a either a Toronto stentless porcine valve (size range: 21-29 mm; n = 74) or an aortic homograft (n = 29). Twenty-eight patients (27%) had either urgent/emergency surgery, 12 (11%) underwent redo surgery, and in 54 cases (52%), the preoperative left ventricular function was significantly impaired (ejection fraction <50%). Forty patients (39%) also underwent concomitant coronary artery bypass grafting. The mean cross-clamp and cardiopulmonary bypass times were 105+/-22 min and 144+/-47 min, respectively. The overall 30-day mortality was 11.6% (n = 12). The 30-day mortality for all elective cases was 5.3%, but for isolated elective AVR was only 2.5%. Using a multivariate model, the only independent predictor of 30-day mortality and medium-term overall mortality was increasing age. The mean follow up period was 3.6 years (range: 0.1-9.3 years), and the Kaplan-Meier actuarial five-year survival was 52%. At follow up, 92% of patients were in NYHA functional classes I and II. CONCLUSION: Stentless AVR in elderly patients is associated with excellent functional and survival outcome in the medium term. Furthermore, in elective cases, age alone should not be a deterrent to the routine use of stentless aortic valves.