Optimal timing of aortic valve replacement for aortic stenosis--are we operating late?

OBJECTIVE: To evaluate the adherence to current guidelines for surgery in patients with aortic valve stenosis. DESIGN: From 1 January 1997 to 31 May 1999, 99 patients were accepted for aortic valve surgery with preserved left ventricular function and normal coronary angiogram. On admission for operation, 20 patients were evaluated regarding symptoms, exercise capacity, and left ventricular morphology and function. RESULTS: There were 14 men and 6 women, mean age 64.3 years. Years from symptom onset varied from 2.1 to 3.2. Dyspnoea was the most common limiting symptom. Thirty per cent of the patients were classified as NYHA IIIB. Physical capacity was reduced to 79% of the expected. Left ventricular hypertrophy was present in 14/20 patients. Left ventricular systolic function was reduced with mean ejection fraction of 0.46. Diastolic dysfunction (E/A ratio <1) was present in 12 patients. CONCLUSION: Many patients accepted for aortic valve replacement due to aortic stenosis show advanced disease and are referred for surgery later in the disease process than is recommended in the current guidelines.

Long-term follow-up of morbidity and mortality after aortic valve replacement with a mechanical valve prosthesis.

AIMS: The aim of this study was to determine the incidence of valve-related complications in patients with a mechanical aortic valve prosthesis and to identify risk factors for an adverse outcome. METHODS AND RESULTS: In the 424 patients, event-free survival rates 5 and 10 years after aortic valve replacement were 62% and 37%, respectively. The linearized incidence of thromboembolic events was 4.4% per patient-year, and of anticoagulant-related haemorrhage 8.5% per patient-year. Advanced NYHA functional class, atrial fibrillation, pure aortic regurgitation and thromboembolism prior to surgery decreased event-free survival. A history of pre-operative thromboembolism increased the risk for a first embolic event after aortic valve replacement (relative hazard [RH] 3.2), but was even more strongly associated with the risk for repeated events (> or =2 events, RH 5.4). After each thromboembolic episode that occurred, the risk for a subsequent one was increased. The risk for at least one, and up to three or more haemorrhages was increased in patients with a pre-operative history of bleeding (RH 3.3-5.1) and of atrial fibrillation (RH 1.8-3.9). The risk for a subsequent event was increased by a history of repeated haemorrhages, a short interval since previous bleeding, and high age. CONCLUSIONS: There were few factors strongly related to valve related morbidity. However, previous bleedings and previous thromboembolism were powerful risk factors for repeated events.

Observed and relative survival after aortic valve replacement.

OBJECTIVES: We sought to evaluate the effects of a number of factors that can potentially determine the optimal time for aortic valve replacement (AVR) and the observed and relative survival after the operation. BACKGROUND: Aortic valve replacement is performed in patients within a wide age span, but the proportion of elderly patients is increasing. In survival analyses, adjustment for the effects of age is therefore essential. Analysis of relative survival provides additional information on excess or disease-specific mortality and its risk factors. METHODS: Survival was analyzed in 2,359 patients (1,442 without and 917 with concomitant coronary artery bypass graft surgery) undergoing their first AVR. By relating observed survival to that expected among the general Swedish population stratified by age, gender and five-year calendar period, the relative survival and disease-specific survival were estimated. RESULTS: Early mortality after AVR (death within 30 days) was 5.6%. Relative survival rates (excluding early deaths) after 5, 10 and 15 years were 94.6%, 84.7% and 74.9%, respectively. There was an excess risk of dying during the entire follow-up period. Advanced New York Heart Association functional class, preoperative atrial fibrillation and pure aortic regurgitation were independent risk factors for observed and relative survival. Patients in the oldest age group showed decreased observed survival but excellent relative survival. CONCLUSIONS: Old age was not a risk factor for excess mortality after AVR, whereas atrial fibrillation decreased relative survival substantially.

Long-term follow up study on 64 elderly patients after balloon aortic valvuloplasty.

BACKGROUND AND AIMS OF THE STUDY: The aims of this study were to evaluate symptomatic improvement and event-free/overall survival after balloon aortic valvulotomy in patients with significant sclerotic aortic valve stenosis. METHODS: Sixty-four patients with calcified aortic stenosis, in NYHA class III-IV, and of mean age 79.0 years, underwent a total of 75 scheduled attempts at balloon aortic valvulotomy, with single balloon catheters between December 1987 and June 1993. Patients were either considered as poor surgical candidates or themselves preferred such valvulotomy. RESULTS: Periprocedural major complications, including death in 6%, occurred in association with 16% of the procedures. Among 57 patients in whom initial dilatation was successful, the average period of symptom relief was 9.4 months (median 7.0, range: 0 to 47 months). Independent predictors for longer duration of symptom relief and survival were systolic arterial pressure > 115 mmHg and female gender; ejection fraction > or = 30% was only predictive of survival. Actuarial survival rates at one, two and three years were 77, 48 and 36% respectively. CONCLUSIONS: Balloon aortic valvulotomy is followed by a short period of symptomatic relief and carries a low periprocedural mortality, but considerable morbidity. By comparison, aortic valve replacement patients aged over 70 and with serious physical limitations (NYHA class IIIB-IV) showed much better overall survival. As contraindications to surgery are in most cases relative, aortic valve replacement should always be considered as the only choice in the surgical decision-making.

Long-term relative survival after primary heart valve replacement.

OBJECTIVE: Determination of the optimal timing of primary heart valve replacement is an important issue. The present paper provides a synopsis over early and late survival after primary heart valve replacement, including an evaluation of the excess mortality among heart valve replacement patients compared with the general population. METHODS: Survival was analyzed in 2365 patients (1568 without and 797 with concomitant coronary artery bypass grafting (CABG)) who underwent their first heart valve replacement. Observed survival was related to that expected among persons from the general Swedish population stratified by age, sex, and 5-year calendar period, to calculate the relative survival and estimate the disease-specific survival. RESULTS: Early mortality (death within 30 days after surgery) was 5.9% after aortic valve replacement, 10.4% after mitral valve replacement and 10.6% after combined aortic and mitral valve replacement. Relative survival rates (excluding early deaths) were 84% 10 years after aortic, 68.5% after mitral and 80.9% after both aortic and mitral valve replacement. A multivariate model based on observed survival rates was produced for each group, using the Cox proportional hazards model. Concomitant CABG, advanced New York Heart Association (NYHA) class, preoperative atrial fibrillation, pure aortic regurgitation and higher age increased the late observed survival after aortic valve replacement. NYHA class was the only factor independently related to observed late deaths after mitral valve replacement, and mitral insufficiency the only corresponding factor after both aortic and mitral valve surgery. CONCLUSION: The use of relative survival rates tended to modify the difference between subgroups compared with observed survival rates. Relative survival rates reduced the effect of concomitant CABG on survival, but enhanced for example the effect of aortic regurgitation. In patients > or = 70 years of age and patients submitted to aortic or mitral valve replacement with mild or no symptoms, the survival rate was similar for many years to that in the Swedish population at large.

The effects of simvastatin and pravastatin on objective and subjective measures of nocturnal sleep: a comparison of two structurally different HMG CoA reductase inhibitors in patients with primary moderate hypercholesterolaemia.

1. It has been suggested that HMG CoA reductase inhibitors which are administered as inactive, lipophilic lactones (e.g. simvastatin) have a greater propensity to evoke nocturnal sleep disturbances than pravastatin, an inhibitor given in the active, hydrophilic, open-acid form. 2. The effects of 4 weeks treatment with equipotent doses of simvastatin (20 mg day-1) and pravastatin (40 mg day-1) have been compared using polysomnography and subjective sleep assessments in a double-blind, placebo-controlled, two-period, incomplete block design study involving 24 male patients with primary moderate hypercholesterolaemia (mean LDL cholesterol 5.11 mmol l-1). 3. Analysis of sleep EEG measures relevant to insomnia provided no evidence of significant differences between pravastatin, simvastatin and placebo, except in terms of entries and latency to stage I sleep. The number of entries to stage I sleep was significantly greater after simvastatin treatment than after either pravastatin or placebo (P < 0.05), but by contrast the latency to stage I sleep was significantly prolonged only in the pravastatin group (P < 0.05 vs placebo). 4. Subjective ratings of sleep initiation, maintenance and quality made during and after therapy were not significantly different between the three treatment groups. 5. It appears that the inherent hydrophobicity of simvastatin does not increase the occurrence of sleep disturbances in this patient population at a dose shown to elicit a characteristic hypolipidaemic response.