Pulmonary function and immediate and late outcome after coronary artery bypass surgery.

AIM: The aim of this study was to evaluate whether pulmonary function as assessed by spirometry affects the immediate and late outcome after isolated coronary artery bypass surgery (CABG). METHODS: Data on preoperative percentages of the predicted forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were retrieved from a series of 1848 patients who underwent isolated CABG. Pulmonary disease was defined according to EuroSCORE criteria. RESULTS: Logistic regression showed that percentage of predicted FVC was an independent predictor of in-hospital mortality along with estimated glomerular filtration rate, age and extracardiac arteriopathy. Cox regression analysis showed that pulmonary disease and percentages of predicted FVC were independent predictors of late overall mortality. Percentage of predicted FVC < 70% (at 10-year: 63.8% vs. 74.3%, Cox regression analysis: P = 0.014, RR 1.50, 95%C.I. 1.08-2.08) and pulmonary disease (at 10-year: 58.0% vs. 76%, Cox regression analysis: P < 0.0001, RR 1.75, 95%C.I. 1.29-2.39), but not percentage of predicted FEV1 < 70%, were associated with a marked decrease in late survival. CONCLUSION: This study confirmed the significant, negative prognostic impact of pulmonary disease on the immediate and long-term survival after isolated CABG.

Significance of graft occlusion and coronary atherosclerosis 5 years after coronary artery bypass grafting. A quantitative angiographic study with serial exercise testing.

OBJECTIVE: To evaluate the relative importance of graft occlusions and progression of atherosclerosis in coronary arteries as causes of the occurrence of angina pectoris and impairment of physical performance 5 years after coronary artery bypass surgery. DESIGN: A 5-year follow-up study. SETTING: University hospital in south-western Finland. SUBJECTS: Altogether, 174 consecutive electively operated bypass patients. MAIN OUTCOME MEASURES: Serial clinical evaluation and bicycle exercise tests (pre-operatively, at 6 months, and at 1 and 5 years). Quantitative coronary angiography pre-operatively and 5 years after the surgery. RESULTS: Subjects with patent grafts had fewer angina pectoris symptoms at the 5-year follow-up (24 vs. 52%, P = 0.001) and were treated less frequently with long-acting nitrates (3 vs. 15%, P = 0.037) than subjects with graft occlusions. Fewer of them were in classes II-III of the functional classification of the Canadian Cardiovascular Society (39 vs. 74%, P = 0.001). The exercise test was interrupted less often because of chest pain (23 vs. 41%, P = 0.03) and improvement in exercise test variables during the follow-up period was significantly greater in subjects with patent grafts (P<0.002). Amongst patients without graft occlusions, those with new > or =50% diameter stenoses in coronary arteries were more often in functional classes II-III (59 vs. 32%, P = 0.03) than those without new stenoses, but the groups were similar with respect to angina pectoris and exercise tests variables. In patients with graft occlusions, those with and without new > or =50% diameter stenoses were similar with respect to functional class, angina pectoris and exercise test variables. CONCLUSIONS: Angina pectoris and impairment of physical capacity 5 years after coronary artery bypass grafting are mainly due to occlusion of bypass grafts and not to progression of atherosclerosis in coronary arteries.

Angiographic changes in saphenous vein grafts and atherosclerosis risk factors. A 5-year study with serial measurements of serum lipids and lipoproteins.

The association between cardiovascular risk factors and stenosis or occlusion of saphenous vein grafts was analysed in a prospective 5-year study of 176 unselected patients with coronary artery bypass grafting (CABG). Methods included serial measurements of serum lipids and lipoproteins, determination of apolipoprotein E phenotype, lipoprotein (a) levels 5 years postoperatively, and subcutaneous fat biopsy to determine the fatty acid composition before and one year after CABG. Graft angiography with quantitative analysis of angiograms was performed at the end of follow-up. A coronary artery with diameter < or = 1.5 mm was associated with occlusion of vein grafts (p < 0.01). The mean levels of serum lipids and lipoproteins, other traditional risk factors for atherosclerosis, and subcutaneous fatty acid composition were similar in patients with and without graft occlusion, and similar when the maximum diameter of non-occluded grafts was < 50% vs > or = 50%, and < 25% vs > or = 25%. High lipoprotein (a) concentration tended to be associated with obstructive changes in vein grafts. Our data indicate that, because lipids, lipoproteins and other traditional cardiovascular risk factors do not predict occlusion or stenosis of saphenous vein grafts five years after CABG, it is not currently possible to predict directly from the levels of these risk factors which patients are likely to benefit from pharmacological or other interventions.

Components of the insulin resistance syndrome are associated with progression of atherosclerosis in non-grafted arteries 5 years after coronary artery bypass surgery.

AIMS: Risk factors for progression of atherosclerosis in non-grafted coronary arteries were examined in a prospective 5-year follow-up study of 228 consecutive coronary artery bypass surgery patients, with the main emphasis on insulin resistance syndrome. METHODS AND RESULTS: Serum lipids and lipoproteins were measured pre-operatively and 1, 2, 3 and 5 years after surgery; and a baseline oral glucose tolerance test with plasma insulin determinations was performed pre-operatively. Progression of atherosclerosis was assessed by means of computer-based quantitative coronary angiography. Compared to subjects without progression, the patients with progression of atherosclerotic lesions had a higher body mass index both at baseline (P = 0.022) and at 5 years (P = 0.007), were more often treated for hypertension at baseline (P = 0.008) and at 5 years (P = 0.012), used diuretics more often during the follow-up period (P = 0.002), had a larger blood glucose area under the curve (P = 0.015) and a lower insulin sensitivity index (P = 0.006) in the baseline oral glucose tolerance test, had a higher serum total cholesterol concentration at baseline (P = 0.044), and a higher serum triglyceride concentration (P = 0.005) during the whole follow-up period. Clustering of the components of insulin resistance syndrome at baseline was more frequently found in patients with progression of atherosclerotic lesions than in patients without progression (P = 0.025). For example, for patients with < or = 1 component, the risk of progression was 17%, while for patients with > or = 5 components the risk was 67%. As compared to the other patients, those with new atherosclerotic lesions had a lower insulin sensitivity index at baseline (P = 0.033), and a lower serum high density lipoprotein cholesterol concentration during the follow-up period (P = 0.033). CONCLUSION: In addition to high serum cholesterol, the components of the insulin resistance syndrome are associated with progression of atherosclerosis in non-grafted coronary arteries 5 years after coronary artery bypass surgery.

Quality of life and return to work 5 years after coronary artery bypass surgery. Long-term results of cardiac rehabilitation.

BACKGROUND: Rehabilitation is an important part of the treatment of patients with ischemic heart disease. Therefore, many patients undergoing coronary artery bypass surgery (CABS) also participate in cardiac rehabilitation programs. This study was conducted to investigate whether rehabilitation influences quality of life and work status after CABS. METHODS: Consecutive patients undergoing elective CABS were randomly assigned to a rehabilitation group (R, N = 119) and a hospital-treatment group (H N = 109). All patients received usual medical care. Group R participated in a rehabilitation program based on exercise and counseling. The follow-up time was 5 years. The measured domains of health-related quality of life were heart symptoms, functional class, exercise capacity, use of medication, depression, the patients' perception of health, and overall life situation. The Nottingham Health Profile as a measure of perceived distress was used. RESULTS: Symptoms, use of medication, exercise capacity, and depression scores did not differ between groups R and H. Five years after the CABS, the patients in group R reported less restriction in physical mobility on the Nottingham Health Profile than patients in group H (P = 0.005), and more patients in group R than in group H perceived their health (P = 0.03) and overall life situation (P = 0.02) as good. The increase in the proportion of subjects working was higher in group R than group H at 3 years after the CABS (P = 0.02), but not at other follow-up times. CONCLUSION: A cardiac rehabilitation program in conjunction with usual medical care after CABS may induce a perception of improved health. The influence on return to work is limited.

Effects of five years of cardiac rehabilitation after coronary artery bypass grafting on coronary risk factors.

Coronary risk factors were studied in 119 patients randomly assigned to cardiac rehabilitation and compared with 109 patients receiving standard care alone after coronary artery bypass grafting. The long-term impact of rehabilitation on risk factors was modest in patients undergoing elective coronary surgery.

Enalaprilat in acute intractable heart failure after myocardial infarction: a prospective, consecutive sample, before-after trial.

OBJECTIVE: To evaluate the acute effects of intravenous enalaprilat infusion in critically ill patients with intractable heart failure after acute myocardial infarction. DESIGN: Prospective, consecutive sample, before-after trial. SETTING: Medical intensive care unit in a university hospital. PATIENTS: Eight consecutive patients with intractable acute heart failure after acute myocardial infarction. All study patients continued receiving inotropic, vasodilating, and diuretic medication at a constant rate. Six patients received steady intermittent mandatory ventilation and two patients were on a continuous positive airway pressure mask during the investigation, all with constant positive end-expiratory pressure. Heart failure was defined as intractable if the pulmonary artery occlusion pressure remained > 20 mm Hg despite this conventional therapy. INTERVENTIONS: Enalaprilat was infused at a rate of 1 mg/hr until the pulmonary artery occlusion pressure decreased by > or = 20%. MEASUREMENTS AND MAIN RESULTS: Central hemodynamics, oxygenation, and hormonal regulation (plasma renin activity, plasma norepinephrine, epinephrine, endothelin, atrial natriuretic peptide, and vasopressin concentrations, serum angiotensin-converting enzyme activity, and serum concentrations of aldosterone) were assessed at baseline before enalaprilat infusion, and repeatedly during 2 hrs after the infusion. The statistical analysis was performed with analysis of variance for repeated measurements. Enalaprilat infusion (median dose 0.3 mg and infusion time 21 mins) caused significant but short-lasting decreases in pulmonary artery occlusion pressure (p = .007), mean arterial pressure (p = .003), mean pulmonary arterial pressure, and rate pressure product. These findings coincided with inhibition of serum angiotensin-converting enzyme activity, an increase in plasma renin activity, and a decrease in plasma endothelin concentrations (p = .041). Enalaprilat had no significant effects on the other hormones studied. Cardiac output and stroke volume index, venous admixture, oxygen extraction ratio, and mixed venous and arterial oxygen saturations remained unchanged. CONCLUSIONS: Adding enalaprilat to conventional therapy makes it possible to transiently relieve pulmonary congestion while maintaining cardiac function and systemic oxygenation. The decrease in plasma endothelin concentrations may have further clinical implications, because endothelin is known to have potent vasoconstricting effects on the coronary circulation and it may also contribute to the extension of myocardial infarction. Whether these observed benefits can be maintained with repeated bolus injections or with continuous infusion of enalaprilat, remains to be settled.

Haemodynamic effects of enalaprilat and preload in acute severe heart failure complicating myocardial infarction.

In this study, the acute haemodynamic effects of angiotensin converting enzyme (ACE) inhibition with intravenous enalaprilat alone or in combination with preload restoration were determined in patients with severe heart failure complicating acute myocardial infarction. Ten patients with raised pulmonary arterial wedge pressure (PAWP > or = 18 mmHg) were first studied during constant conventional vasodilation with diuretic and inotropic medication, by monitoring central haemodynamics and arterial blood gases. The same variables were measured before enalaprilat infusion, after preload reduction with enalaprilat (1 mg.h-1, rate doubled every 30 min until PAWP decreased > or = 25% or up to total cumulative dose of 10 mg) and after preload restoration with fluid loading (4% albumin given 15 ml.min-1 to restore PAWP to baseline) during continuous low dose enalaprilat infusion. Enalaprilat alone (median dose 0.9 mg) reduced significantly the PAWP (from 25 to 17 mmHg; P = 0.004), the mean arterial pressure (from 87 to 83 mmHg; P = 0.008), the mean pulmonary arterial pressure and the right atrial pressure. The cardiac index, stroke volume index and systemic vascular resistance index remained unchanged. Preload restoration during continuous enalaprilat infusion (median dose of 4% albumin 230 ml, and enalaprilat 0.2 mg) did not further enhance left ventricular function; rather, there was a nearly significant decrease in myocardial perfusion pressure. Arterial oxygenation remained unchanged throughout the study. In conclusion, adding intravenous enalaprilat to conventional therapy makes it possible to relieve pulmonary congestion while maintaining the cardiac function and arterial oxygenation. Preload restoration during continuous ACE inhibition offers no further advantages, and may have adverse effects, since the myocardial perfusion pressure may fall.