Abstract
Arterial hypertension is thought to be associated with reduced coronary vasodilator
reserve in the coronary microcircula-tion. Increased ventricular mass and coronary
arteriolar abnormalities are the dominant features in patients with severe hypertension,
while large-vessel coronary disease is the predominant feature in patients with mild
hypertension. In the present study we have evaluated how hypertension influences the
outcome of coronary artery bypass grafting (CABG), with emphasis on patients with
preoperative left-ventricular ejection fraction (LVEF) ≤ 25%. Between Januar 1,1990
and November 1,1994, 77 consecutive patients with LVEF ≤25% (Hypertensive, n = 38
[group 1] and normotensive, n = 39 [group II]) underwent CABG. During the same time
period 2289 patients with LVEF > 25 % underwent CABG (Hypertensive, n = 870 [group
III] and normotensive, n = 1419 [group IV]) and were studied for comparison. Mean
age (64 years), sex distribution (86% men), and other classical risk factors did not
differ between the groups, except a higher incidence of insulin-dependant diabetes
in patients with LVEF ≤ 25%. There were 18% reoperative CABG, 91 % of the patients
were Canadian Cardiovascular Society's (CCS) angina class 3 and 4 preoperatively,
38% had unstable angina, and 35% underwent urgent surgery (within 24 hours of admission).
Angiography and Operation data did not differ significantly between the groups. Hospital
mortality in group I was 5.3% and in group II 15.4%, p < 0.008. In group III it was
6.3% and in group IV 2.2%, p < 0.001. Postoperative low cardiac Output occurred in
18% (group I) and 39% (group II), p < 0.05, and only in 5% in groups III and IV,p
< 0.001. Non-fatal myocardial infarction and other postoperative complications revealed
no group differences. LVEF and CCS class improved from 1 month postoperatively in
groups I and II, however, significantly more in group I (hypertensives), p < 0.001.
Hypertensive patients with poor left-ventricular function preoperative to were found
to have a lower hospital mortality and incidence of postoperative low cardiac Output
than normotensiven with LVEF ≤ 25%. Hypertensive patients also had a better improvement
of their left-ventricular function and CCS class than normotensiven. Left-ventricular
hypertrophy and previous myocardial infarction were predictors for mortality in patients
with LVEF > 25%. Patients with LVEF ≤ 25% showed the same tendency, though not statistically
significant.
Key words
Arterial hypertension - Coronary artery disease - Coronary artery bypass grafting
- Poor left-ventricular function
