ABSTRACTS

THURSDAY, MARCH 19, 1981 AM SURGERY FOR CORONARY ARTERY DISEASE-2 10:30- 12:oo

FACTORS AFFECTING MORTALITY AFTER MITRAL VALVE REPLACEMENT COMBINED WITH CORONARY BYPASS GRAFTING Bernard Gersh, MD, FACC; Francisco J. Puga, MD; Ronald E. Vlietstra, MD, FACC; Lila R. Elveback, PhD; Steven L. Yeager, MD; William D. Edwards, MD; Gordon K. Danielson, MD, FACC; James R. Pluth, MD, FACC. Mayo Clinic, Rochester, MN.

At the Mayo Clinic from 1972-1978, the 30-day mortality for isolated mitral valve replacement (MVR) was 5.3% (41 of 779), whereas that for MVR plus coronary bypass graft surgery (CABG), 1970-1978, was 13.3% (10 of 75). The aim of this study was to identify by multivariate methods the factors resulting in the high early mortality in the MVR plus CABG group. Clinical, laboratory, and surgical vari- ables were included. There was a major difference between the sexes: the females were older, had more severe coro- nary artery disease (CAD), had a smaller proportion of diseased vessels grafted, and had a higher early mortality (8 of 22 or 36% versus 2 of 53 or 4% for males). Nine of the 10 early deaths could be identified by means of 3 fac- tors: the Gensini measure of the severity of CAD, the adequacy of left coronary revascularization, and the pres- ence of LV aneurysm. This combination of variables cor- rectly classified 91% of the patients. For rheumatic or ischemic etiology (n=47), the early mortality was 20X, whereas CAD was less severe and there were no deaths in patients with primarily degenerative mitral valve disease (n=20). For the 65 30-day survivors, the subsequent 3-year survival was 71% (51% in females, 76% in males). The cardiothoracic ratio was the only variable that dis- criminated between late deaths and the 3-year survivors. We conclude that the early mortality of MVR plus CABG is markedly influenced by the extent of CAD and the adequacy of revascularization. Late mortality, however, is pre- dominantly affected by ventricular function.

CORONARY ANGIOGRAPHY AND CORONARY ARTERY BYPASS SURGERY IN ELDERLY PATIENTS Bernard Gersh, MD, FACC; Robert L. Frye, MD, FACC; Richard A. Kronmal, PhD; Elizabeth Cardis, BS; Thomas J. Ryan, MD, FACC; Arthur J. Gosselin, MD, FACC; George Kaiser, MD, FACC; Thomas Killip III, MD, FACC, and all participants in the Coronary Artery Surgery Study (CASS).

This study.describes 2,035 patients (pts) 265 years old with coronary artery disease entered in the CASS registry and the complications of coronary angiography and bypass surgery (CABG) in this group. Ages ranged from 65-82 years; 73% were males. The predominant symptom was angina pectoris in 86% and cardiac failure in 6%. In 51X, angina

pectoris was unstable. Angiography documented triple- vessel disease in 53X, double-vessel in 26%, and single- vessel in 17%. Disease of the left main coronary artery (~50% stenosis) was present in 15%. Ejection fraction was ~50% in 32% of pts. Complications of angiography included death in 0.25%, nonfatal myocardial infarction in 0.6%, and neurologic complications in 0.5%. CABG alone was performed in 997 pts (49X), with a hospital mortality of 5%. Pts were divided into three age groups: 1, 65-69 years; 2, 70-74 years; and 3, ~75 years. Results were as follo”s:

No. of Hospital surgical

s- mortality q!.P- 4.5%

221 2 6.3% 41 3 9.8%

We conclude that in patients ~65 years of age, the mortality of coronary angiography is low whereas that of CABG is increased in comparison with a 1.8% hospital mortality in 6,438 CASS pts ~65 years old.

HYPERLIPOPROTEINRMIA (HLP) AS A SIGNIFICANT RISK FACTOR FOR PULMONARY EMBOLISM (PE) IN CORONARY ARTERY BYPASS (CABG) PATIENTS Eric C. Hanson, MD and Frederick H. Levine, MD Massachusetts General Hospital, Boston, MA 02114

Although PE is a rare complication following cardiac surgery, a notable association of PE in hyperlipoprotein- emit patients following CABG prbcedures prompted us to define the incidence of PE in this group. A retrospective study of all patients suffering PE following cardiac sur- gery from 1975 through 1979 was undertaken and lipoprotein profiles of these patients were evaluated. Of over 4,800 patient records, 26 patients (19 male, 7 female) were identified who presented with the definite clinical, laboratory, and radiologic evidence of PE in the post- operative period. Twenty had undergone coronary artery bypass grafting, and the remaining six had undergone other cardiac procedures. Of the 20 CABG patients, 19 (95%) were found to have HLP (14 Type II patients, 70%; 5 Type IV patients, 25%). Only one of the six other patients had HLP, a patient who had an aortic arch aneurysm resection who was Type II. There were four hospital deaths (4/26, 15%), all related to PE and all were Type II patients who had undergone CABG procedures. Since patients with HLP comprise less than 10% of our CABG population the inci- dence of PE in this group is highly significant (p<.UUl). Experimental evidence has shown that patients with HLP, especially Type II, have increased platelet adhesiveness and clotting abnormalities consistent with a hypercoagula- ble state. This retrospective study clinically confirms that finding and suggests that early postoperative anti- coagulation therapy in patients with HLP, particularly Type II, may be indicated to reduce thromboembolic compli- cations.

IMPROVED GRAFT PATENCY WITH ANTIPLATELET DRUGS IN PATIENTS TREATED FOR ONE YEAR FOLLOWING CORONARY BYPASS SURGERY. B Greg Brown, MD,PhD, RamonACukingnan, MD, Lacy Goede,BS, Maylene Wong, MD Henry Fee, MD, Jack Roth,MD, JohnWittig, MD, Joseph Carey: MD, Wadsworth VA Hosp, UCLA, L.A., CA.

Does antiplatelet therapy (APT) improve saphenous vein graft patency? 147 consecutive patients (pts)wereenrolled in a randomized, doubly blinded, risk-stratified, prospec- tive trial comparing aspirin 325 mg tid plus dipyridamole 75 mg tid (A/D), or aspirin (A), with double placebo (P). 123 patients completed surgery, drug initiation 67+27 (SD) hours post-op, 5 clinic visits, and recath at one year. Overall predictors of graft patency were coronary lumen diameter at the point of anastomosis (Dan), the % proximal stenosis in the grafted artery (%S), graft flow (Qg), and the % reactive hyperemia (%RH) after a 15 second raft occlusion. Results, in terms of assigned therapy 9 ARx): APT did notbenefit grafts to arteries with Dans1.5mn, or grafts with Qgs40ml/min or with %RHz 15% above baseline flow. But a substantial trend in favor of APT (A or A/D) was seen in the overall group. Strong favorable trends or statistically significant benefits were seen in certain larse subsets. All qrafts were patent in 57% of 44 pts on

1 A 112.2%ilEi 9.5%+‘(84i l17.2%* (58) /D 16.3%(135) 10.4% &j 8.3%* (84) 20.0% 65) PT 14.4%(250) 9.4%+ 181) 8.9%*(168) 18.7%+ 123) ~2 comparison of drug with P: *=~<.05, +=p<.O2, *=~<.01 I,

The most comnonandgenerallymdstimportantsubsetsof diseasedarteriesarethosewith Dan>l.h orwhichrequire Qg>4Dnl/min. Antiplatelettherapyreducesby50-612theearly occlusion of graftstothosearteries. Thus post-op APT is recommended, unless contraindicated,formostbypass patients.

494 February 1991 The American Journal of CARDIOLOGY Volume 47