PIERRE ROBERT, PH D. BERNARD R. CHAITMAN ..... I. MCINTOSH HD, GARCIA JA: The first decade of aortocoronary bypass grafting,. 1967-1977. A review.
Factors predicting working status after aortocoronary bypass surgery NICOLAS DANCHIN, MD PAUL DAVID, MD MARTIAL G. BOURASSA, MD PIERRE ROBERT, PH D BERNARD R. CHAITMAN, MD The working status of 1 165 patients aged 59 years or socioeconomiques analysAs, un non-emploi de longue less (mean 49.8 years) was evaluated 7 to 77 months dur6e avant l'op6ration, un emploi prbop6ratoire exi(mean 36 months) after aortocoronary bypass surgery. geant un effort physique iniportant et un faible Although 76% of the patients eventually returned to niveau d'6ducation 6taient, dans l'ordre, les plus forts work, only 56% were working 6 months after their indices prbvisionnels d'un non-emploi postopbratoire. operation. The proportion of patients working peaked Parmi les facteurs cliniques une maladie noncarat 2 years after the operation (at 66%) and decreased dur6e de l'angine de poitrine ont influencA l'occupation progressively to 56% at 4 years and 53% at 5 years des patients aprAs l'op6ration. Les auteurs concluent without ever reaching the proportions that applied 12 qu'il y a lieu de tenter de modifier certains de ces and 6 months before the operation (84% and 69% facteurs avant et aprAs l'op6ration de pontage aorrespectively). Multivariate analysis identified three tocoronarien afin de voir si le pourcentage des sujets socioeconomic and three clinical variables as predict- qui retournent au travail peut Atre am6liorb chez des ing the working status at 6 months and at yearly points during the first 4 years after the operation. Of the socioeconomic variables analysed, preoperative unemployment of long duration, a preoperative occupation that required strenuous physical effort and a low level of education were, in that order, the strongest predictors of postoperative unemployment. Among the clinical variables, associated noncardiovascular illness and the severity and duration of angina pectoris independently influenced the patients' postoperative working status. The authors conclude that modification of some of these variables should be attempted both before and after aortocoronary bypass surgery to see whether the rate of return to employment after the operation can be improved in selected patients.
L'occupation de 1165 patients ag6s de 59 ans ou moins (moyenne de 49.8 ann6es) a bt 4valu6e de 7 A 77 mois (moyenne de 36 mois) apres une operation de pontage aortocoronarien. Bien que 76% des patients soient 6ventuellement retourn6s au travail, seulement 56% travaillaient 6 mois aprAs leur opbration. Le pourcentage des patients au travail a atteint un sommet 2 ans aprAs l'opbrationi (66%) et declina progressivement A 56% apres 4 ans et A 53% aprAs 5 ans sans jamais atteindre les chiffres prevalant 12 et 6 mois avant l'op6ration (84% et 69% respectivement). Une analyse statistique multifactorielle a identifie trois facteurs socioeconomiques et trois facteurs cliniques susceptibles de prAdire l'occupation des patients apres 6 mois et a intervalles annuels durant les 4 premieres ann6es qui ont suivi l'op6ration. Parmi les facteurs From Institut de Cardiologie de Montreal and departement de m6decine, faculte de m6decine and d6partement d'informatique et recherche operationnelle, faculte des arts et des sciences, universitt de
Montreal Reprint requests to: Dr Paul David, Institut de Cardiologie de Montreal, 5000 est, rue B6langer, Montr6al, PQ HIT IC8
patients choisis.
Although complete or partial relief of angina pectoris is noted in 75% to 90% of patients after aortocoronary bypass surgery,' recent reports2-" indicate that a relatively large proportion of patients do not return to gainful employment after undergoing this procedure. These reports also identify some clinical and socioeconomic variables that may influence the postoperative working status of patients. Most of the reported data are limited to the first year after the operation; the longterm work profile of these patients was not described. We therefore determined the percentage of 1320 men who returned to work after this operation and analysed variables that may predict their employment status in the early and late postoperative periods. Material and methods Patient population
Between January 1973 and June 1978, 2026 patients underwent aortocoronary bypass surgery at the Montreal Heart Institute. For our study we excluded women, patients aged 60 years or more, patients who had previously had cardiac surgery and patients requiring associated surgery for valvular heart disease, congenital heart disease or cardiomyopathies. Of the remaining 1320 patients 33 (2.5%) died in the 30 days after the operation. In February 1979 we sent to the 1287 surviving patients a detailed questionnaire on their social, economic and working status before surgery and on their working status after surgery. By the end of August 1979 we had answers for 1234 patients (96%). Of those surveyed 74 had died; the work status of 17 of them was unknown. Thus, we were able to analyse the reported postoperative working status of 1217 patients. Of the respondents, 52 did not indicate whether they were working at 6 months or at CMA JOURNAL/FEBRUARY 1, 1982/VOL. 126
255
yearly points after the operation. Thus, the subsequent analysis included 1165 patients aged 59 years or less (mean 49.8 years) followed up for 6 months, 1068 for 1 year, 794 for 2 years, 598 for 3 years, 391 for 4 years and 181 for 5 years. The follow-up period ranged from 7 to 77 months (mean 36 months). Variables studied We studied a total of 27 clinical, arteriographic, surgical and socioeconomic variables. The data for each were recorded by at least two observers after a close review of the original documents, hospital charts and answers to the questionnaire. In addition to the 10 variables listed in Table I we analysed the presence or absence of 10 clinical abnormalities, including a history of myocardial infarction, an abnormal resting elec-
trocardiogram,
a
cardiothoracic ratio
on
the chest
roentgenogram that was greater than 0.50, a history of hypertension, past or present cigarette smoking, diabetes mellitus, a serum cholesterol level greater than 240 mg/dl, a serum triglyceride level greater than 170
mg/dl, abnormal left ventricular function as assessed from the left ventriculogram (wall motion was categorized as normal, hypokinetic or akinetic) and an abnormal ejection fraction (the fraction was classified as more than 0.5, 0.35 to 0.5 or less than 0.35). The patients' angina was classified according to the functional criteria of the New York Heart Association; patients with atypical chest pain were grouped in a fifth category. The duration of cardiovascular illness was calculated as the period from the date on which the first cardiac symptom occurred to the date of the bypass
Table 1-1.nivariate analysis of cinical, angiographic and surgcal varables, and statistical significance of association with working status in 1165 patients at 6 months (653 [56%] were working) and in 598 patients at 3 years (371 [62%] were working) after aortocoronary bypass surgery,
rune after surgery No. of patients
Variable
6 months % working
Functional class of angina 2 3 4 Atypical Age (yr) < 40 40-44 45-49 50-54 55-59 Duration of symptoms (mo)