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Improved longevity due to reduction of sudden death by aortocoronary bypass in coronary atherosclerosis
Insights
Coronary bypass surgery significantly reduced sudden cardiac death in patients with multivessel coronary stenosis compared to medical therapy. This surgical intervention also improved functional capacity and relieved angina, prolonging survival.
Area of Science:
- Cardiology
- Cardiac Surgery
Background:
- Multivessel coronary stenosis poses a significant risk of sudden cardiac death.
- Medical therapy and surgical interventions are primary treatment options.
Purpose of the Study:
- To evaluate the efficacy of coronary bypass surgery in reducing sudden death.
- To compare the long-term prognosis of medical versus surgical therapy in patients with multivessel coronary stenosis.
Main Methods:
- Prospective study comparing 114 medically treated patients (Group I) with 172 surgically treated patients (Group II).
- Patients were matched for age, disease duration, angina, prior myocardial infarction, congestive heart failure, and coronary risk factors.
- Cardiac catheterization and coronary arteriography assessed stenosis extent, ventricular function, and collateral vessels.
Main Results:
- Coronary bypass surgery (Group II) showed a marked reduction in sudden death (6% vs. 24% in Group I, P < 0.05).
- Surgical intervention led to significantly greater symptomatic improvement, including improved functional capacity (69% vs. 12%, P < 0.05) and complete anginal relief (60% vs. 30%, P < 0.05).
- Mortality from congestive heart failure and noncardiac causes did not differ significantly between groups.
Conclusions:
- Effective aortocoronary bypass surgery prolongs survival in patients with multivessel coronary disease.
- The reduction in sudden death may be attributed to decreased incidence of unexpected fatal arrhythmias.
- Surgical intervention offers significant symptomatic benefits beyond mortality reduction.
Abstract:
To evaluate the efficacy of coronary bypass surgery in reduction of sudden death, the prognosis of 286 similar patients with multivessel coronary stenosis was studied prospectively and the results of medical therapy (Group I, 114 patients) were compared with those of surgical therapy (Group II, 172 patients) after cardiac catheterization and coronary arteriography. During 39 months' evaluation of both groups, mortality from congestive heart failure and noncardiac causes did not differ (Group I, 14 percent; Group II, 8 percent) (P greater than 0.05). Sudden was evaluated in the remaining 217 patients (Group I, 96; Group II, 121 patients) who were matched for age (Group I, 52 years; Group II, 51 years); duration of overt coronary disease (Group I, 3.8 years; Group II, 4.0 years); angina pectoris (Group I, 83 percent; Group II, 95 percent); prior myocardial infarction (Group I, 77 percent; Group II, 74 percent); and congestive heart failure (Group I, 30 percent; Group II, 23 percent) (all P greater than 0.05). In addition, the prevalence of coronary risk factors was the same (P greater than 0.05) in both groups (hypertension, cigarette smoking, diabetes mellitus, lipid abnormalities and family history of coronary disease). Importantly, arteriography and catheterization established a similar extent and location of major coronary arterial stenoses and of ventricular dysfunction; two vessel disease (Group I, 32 percent; Group II, 33 percent) and three vessel disease (Group I, 68 percent; Group II, 67 percent); left ventricular end-diastolic pressure (Group I, 13; Group II, 14 mm Hg);cardiac index (Group I, 2.85; Group II, 2.91 liters/min per m2); and coronary collateral vessels (Group I, 58 percent; Group II, 61 percent) (all P greater than 0.05). Fifty-six percent of patients in Group II had multiple bypass grafts and a late patency rate (average 21 months) of 87 percent of one or more grafts. During subsequent prospective evaluation of over 3 years, bypass surgery provided greater symptomatic benefit of improved functional capacity (Group I, 12 percent; Group II, 69 percent) (P less than 0.05) and complete anginal relief (Group I, 30 percent; Group II, 60 percent) (P less than 0.05). Moreover, bypass surgery was associated with marked reduction in sudden death (Group I, 24 percent; Group II, 6 percent) (P less than 0.05). Thus, in patients with multivessel coronary disease carefully matched for clinical factors, hemodynamics, atherogenic precursors and coronary pathoanatomy, effective aortocoronary bypass surgery appeared to prolong survival by decreasing the incidence of sudden death, possibly by a decrease of unexpected fatal arrhythmias.