Prognostic value of angiographic indices of coronary artery disease from the Coronary Artery Surgery Study (CASS).

The Coronary Artery Surgery Study, CASS, enrolled 24,959 patients between August 1975 and June 1979 who were studied angiographically for suspected coronary artery disease. This paper compares the prognostic value for survival without early elective surgery of eight different indices of the extent of coronary artery disease: the number of diseased vessels, two indices using the number of proximal arterial segments diseased, two empirically generated indices from the CASS data, and the published indices of Friesinger, Gensini, and the National Heart and Chest Hospital, London. All had considerable prognostic information. Typically 80% of the prognostic information in one index was also contained in another. Our analysis shows that good prediction from angiographic data results from a combination of left ventricular function and arteriographic extent of disease. Prognosis may reasonably be obtained from three simple indices: the number of vessels diseased, the number of proximal arterial segments diseased, and a left ventricular wall motion score. These three indices account for an estimated 84% of the prognostic information available. 6-yr survival varies between 93 and 16% depending upon the values of these three indices.

Doppler indexes of left ventricular filling after exercise in 50-year-old healthy persons.

Exercise-induced myocardial ischemia has been shown to alter left ventricular (LV) diastolic filling. An abnormal response of Doppler indexes of LV filling during and after exercise testing has been demonstrated to be a sensitive marker of coronary artery disease. A paucity of data is available regarding reference values and the physiological variation in LV filling indexes after exercise in healthy subjects of similar age. We therefore evaluated 77 healthy subjects (33 men and 44 women) aged 50 years by Doppler echocardiography at rest and 15 and 60 minutes after exercise testing. The peak velocity of early diastolic filling (E-wave), the peak velocity of atrial filling (A-wave), the early to atrial peak velocity (E/A) ratio and the deceleration time of early velocity were measured. There was a decrease in the E/A ratio 15 minutes after exercise compared with the E/A ratio at rest in women (1.13 +/- 0.23 vs 1.23 +/- 0.27; p <0.001) and men (1.03 +/- 0.22 vs 1.15 +/- 0.20; p <0.001). The E/A ratio 60 minutes after exercise did not differ significantly from rest in women (1.23 +/- 0.27 vs 1.18 +/- 0.24; p = NS), but men had a lower E/A ratio 60 minutes after than before exercise (1.04 +/- 0.23 vs 1.15 +/- 0.20; p <0.001). There was no difference in deceleration time of the E-wave before and after exercise. Multivariate analysis revealed that the E/A ratio 15 and 60 minutes after exercise was strongly independently associated with the E/A ratio at rest (p <0.001) and heart rate 15 and 60 minutes after exercise (p <0.005) in both women and men. It is concluded that there is a physiological decrease in the E/A ratio 15 minutes after exercise in healthy subjects, and Doppler LV filling indexes after exercise are strongly associated with LV filling indexes at rest and with heart rate.

Distribution patterns of ventricular premature complexes at different heart rates.

The relation between distribution patterns of ventricular premature complexes (VPCs) and heart rate in Holter recordings abundant in VPCs was analyzed using computer-assisted determination of the number of interectopic sinus beats at different heart rates. Within the complete 24-hour heart rate spectrum, zones were demonstrated that were characterized by manifest or concealed bigeminy or manifest or concealed trigeminy. Bigeminy zones were found in 26 and trigeminy zones in 21 of 42 patients. Bigeminy zones were found at a significantly lower heart rate, on the average, then trigeminy zones. In 10 patients both bigeminy and trigeminy zones were observed. Bigeminy and trigeminy zones probably correspond to the distribution patterns of VPCs predicted from modulation of a pacemaker and reflected reentry, both of which can be induced by electrotonically mediated impulses across a zone of impaired conduction in isolated bundles of Purkinje fibers. The bigeminy and trigeminy zones will correspond at least partly to the entrainment zones found during electrotonic modulation of parasystolic foci. The bigeminy zones will correspond to 2:1 entrainment and the trigeminy zones mainly to 3:1 entrainment.

An echocardiographic study comparing male Swedish elite orienteers with other elite endurance athletes.

Between 1979 and 1992, there were 16 known cases of sudden unexpected cardiac death among young Swedish orienteers, whose autopsies showed myocarditis to be a common finding. Therefore, 96 elite orienteers and 47 controls underwent echocardiography, showing left ventricular wall motion abnormalities in 9% of the orienteers compared with 4% in the controls.

Effect of coronary bypass surgery on survival patterns in subsets of patients with left main coronary artery disease. Report of the Collaborative Study in Coronary Artery Surgery (CASS).

The 3 year cumulative survival rate of 1,492 patients with left main coronary artery disease (50 percent or greater stenosis of luminal diameter) enrolled in the Collaborative Study in Coronary Artery Surgery (CASS) was 91 percent for the surgical group and 69 percent for patients treated medically (p less than 0.0001). Mortality was significantly greater in patients with impaired left ventricular function. The difference between medical and surgical therapy was significant for patients who had normal, moderately abnormal and severely impaired left ventricular function and for patients with stenosis of the left main coronary artery of 50 to 59, 60 to 69, 70 to 79 and 80 percent or greater. Aortocoronary bypass surgery did not significantly improve survival in patient subgroups who had (1) a nonstenotic dominant right or balanced coronary circulation, (2) a stenotic dominant right coronary artery and normal left ventricular function, and (3) left main coronary stenosis of 50 to 59 percent and normal or mildly abnormal left ventricular function. The Cox proportional hazards model was used to select baseline variables that were independent predictors of long-time mortality. The model selected left ventricular score, age, congestive heart failure score, hypertension, percent left main coronary arterial stenosis and coronary arterial dominance as the baseline variables most predictive of long-term survival. A clinical and angiographic prognostic risk index developed from these six baseline variables showed significantly improved survival for the surgical cohort in each of four risk categories. In the best and worst risk category, the 3 year survival rate was 97 and 82 percent, respectively, for the surgical group and 85 and 34 percent, respectively, for the medical group (p less than or equal to 0.0002). The data from this observational study show that coronary bypass surgery prolongs life in most patients with left main coronary artery disease, particularly those who have severe narrowing of the left main coronary artery or impaired left ventricular function. The results permit a better understanding of the natural history of left main coronary artery disease and permit a more accurate estimate of long-term survival for individual patients through the use of a clinical-angiographic risk index.

Differentiation of fibres in human masseter, temporal and biceps brachii muscles. A histochemical study.

Masseter, temporal and biceps brachii muscles were histochemically evaluated for fibre type differentiation on 19 aborted fetuses (gestational ages 15-23 weeks), in 2 premature infants of 34 and 36 weeks gestation and in 2 fullterm stillborn infants. There was no convincing evidence of fibre type differentiation in the masticatory muscles before 22 weeks' gestation while a fairly distinct differentiation was seen in biceps brachii specimens at 16 weeks' gestation with ATPase at pH 4.35. Around 22 weeks two types of fibre were found in all specimens with ATPase at pH 4.35. With regular ATPase (pH 9.4) there was a relatively weak difference in staining between different types of fibre in the masticatory muscles. In biceps brachii Type I and Type II were demonstrated. Neonatally 3 levels of staining were seen in biceps brachii with regular ATPase (pH 9.4); while ATPase pH 4.35 and 4.6 demonstrated the subtypes IIB and IIC. In the masticatory mucles only 2 levels were recognized with regular ATPase and all type II fibres had the characteristics of Type IIC as seen with with ATPase at pH 4.35.

Histochemical fibre-type profile in the human masseter muscle.

A histochemical characterization of the masseter muscle was performed on biopsy samples of dentate subjects with normal occlusion. There was a continuum of ranges of oxidative and glycolytic capacities of the masseter muscle fibres. Besides the lightly-stained type I and the darkly-stained type II fibres, fibres with intermediate staining reactions for standard ATPase at pH 9.4, IM fibres, were seen in all biopsy samples. IM fibres had some staining characteristics in common with type I, i.e. the reaction for NADH-TR and for ATPase after preincubation at pH 4.6 and 4.2. Like type II fibres they showed strong reaction for menadione-linked alpha-glycerophosphate dehydrogenase and for phosphorylase. The ATPase reaction after preincubation at pH 4.6 did not generally reveal subtypes of type II. It is concluded that the masseter muscle in normal human subjects has a very special fibre composition, with ATPase-IM fibres being a part of the normal fibre population.

Institutional differences in therapeutic decision making in the Coronary Artery Surgery Study (CASS).

This article examines institutional differences in therapeutic decision making in the Coronary Artery Surgery Study (CASS). The initial decision to use medical therapy or coronary artery bypass surgery for coronary artery disease is studied. Data from the CASS registry and a survey of CASS principal investigators were used to examine the effects of institutional characteristics, individual physician characteristics, and decision making responsibility on the recommended therapy, the actual therapy, and the ratio of the observed to expected number of surgeries. The results indicated that the experience and involvement of the surgeon in the decision making process were related to actual and recommended rates of surgery. The percentage of urgent transfers from other hospitals and the percentage of surgical referrals to outside hospitals were related to the ratio of the observed to expected numbers of surgery, an adjusted rate of surgery. A major conclusion of this study is that despite the effects of certain institutional constructs, scientific criteria in the form of clinical and angiographic data are the most important determinants of whether a patient receives coronary artery bypass surgery.

The Fenyö-Lindberg scoring system for appendicitis increases positive predictive value in fertile women--a prospective study in 455 patients randomized to either laparoscopic or open appendectomy.

BACKGROUND: Suspected appendicitis is one of the most common indications for acute laparotomy or laparoscopy. The negative laparotomy and laparoscopy rates are high, often in the range of 15-30%, and especially high in some groups of patients such as women of child-bearing age and young patients. Different scoring systems have been introduced in order to improve diagnostic accuracy. The aim of the present study was to analyse the outcome of the Fenyö-Lindberg scoring system in a prospectively randomized multicenter trial and to analyze how well the score performed in stratified subgroups. METHODS: The variables of the Fenyö-Lindberg scoring system were collected in a prospective study comparing laparoscopic and open surgery in suspected appendicitis and with four participating centers. None of the hospitals had used the scoring system previously. Since surgeons were unfamiliar with the score, they could not use it as a diagnostic aid. When comparing the score with the clinical outcome, retrospectively, the investigators interpreting the score were blinded regarding the surgical outcome. RESULTS: Positive predictive value (PPV) of the Fenyö-Lindberg score was higher than that of the surgeon's clinical diagnosis in the patient cohort [0.90 vs 0.79 (p < 0.001)]. The score demonstrated an improvement of PPV in women [0.83 vs 0.70 (p < 0.01)]. PPV was increased in women between 15 and 50 years of age. In women aged 15-30 years and 31-50 years PPV increased from 0.69 to 0.82 and 0.68 to 0.86, respectively (p < 0.01). Both the sensitivity (0.77) and the specificity (0.69) of the score were, however, low. CONCLUSION: The Fenyö-Lindberg score is an inexpensive clinical tool that may improve the diagnostic accuracy for acute appendicitis in women of childbearing age, which is a group of patients where the diagnostic accuracy usually is low and where the arsenal of diagnostic tools such as computed tomography is limited because of radiation. The low specificity of the score in women of childbearing age must, however, be kept in mind.

Laparoscopic vs open appendectomy in overweight patients.

BACKGROUND: Laparoscopic appendectomy (LA) has been associated with a faster recovery and less postoperative pain than the open technique. However, few data are available on the clinical outcome of LA in overweight patients. METHODS: A group of 106 patients with a body mass index (BMI) > 26.4, representing the upper quintile of 500 prospectively randomized patients, were included in the study. They were randomized to undergo either laparoscopic or open appendectomy (OA). Operating and anesthesia times, postoperative pain, complications, hospital stay, functional index (1 week postoperatively), sick leave, and time to full recovery were documented. RESULTS: In OA, the operating time for overweight patients was significantly longer than that for patients in the normal weight range (40 vs 35 min, p < 0.05). In LA, there was no difference in operating time between the normal and overweight patients. Overweight patients who underwent LA had longer operating and anesthesia times than their OA counterparts (55 vs 40 min, p < 0.001; and 125 vs 100 min, p < 0.001, respectively). Postoperative pain was significantly greater in overweight patients who underwent OA than in those treated with the laparoscopic technique. Postoperative pain was also significantly greater in overweight patients subjected to OA than in patients of normal weight after 4 weeks; the clinical significance may, however, be of less importance since the values are low (0.26 vs 0.09, p < 0.05). There were no significant differences between the two operating techniques in terms of complications. Hospital stay was longer for overweight patients than for normal-weight patients undergoing OA (3.0 vs 2.0, p < 0.01). The functional index did not differ between any group of patients. Sick leave was longer for overweight patients who underwent OA than for normal-weight patients treated with the same technique (17 vs 13 days, p < 0.01). In the laparoscopic group, however, there were no differences between the overweight and normal-weight patients. Time to full recovery was greater in overweight patients subjected to OA than in the overweight patients in the LA group (22 vs 15 days, p < 0.001). CONCLUSION: In this study, overweight patients who were submitted to LA had less postoperative pain and a faster postoperative recovery than overweight patients who had OA. LA also abolished some of the negative effects that overweight had on operating time, hospital stay, and sick leave with the open technique. However, anesthesia and operating times were significantly longer in LA for both overweight patients and those with a normal BMI.

Monotherapy with amlodipine or atenolol versus their combination in stable angina pectoris.

BACKGROUND: The basic cause of angina pectoris is imbalance between the metabolic needs of the myocardium and the capacity of the coronary circulation to deliver sufficient oxygenated blood to satisfy these needs. HYPOTHESIS: The study was undertaken to evaluate whether the effect of combined amlodipine and atenolol therapy on patients with stable angina pectoris and with ST-depression during exercise testing and 48-h ambulatory electrocardiographic monitoring is superior to that of either agent given alone. METHODS: Patients with stable angina pectoris and ST depression during exercise and ambulatory monitoring were randomized to receive amlodipine (n = 116) or atenolol (n = 116), or both (n = 119). All patients were also treated with short- and long-acting nitrates. The design was a double-blind, randomized, triple-arm parallel group study with 10 weeks of administration of the test medication. RESULTS: In terms of time to onset of ST depression > 1 mm, time to onset of angina, total exercise time, maximum achieved workload, and peak intensity of angina, amlodipine and atenolol alone were as effective as their combination. During ambulatory monitoring, atenolol was more effective than amlodipine regarding total time and number of ST-depression episodes, and as effective as the combined drugs. CONCLUSION: For individual patients with stable angina pectoris, combination of a beta blocker with a calcium antagonist is not necessarily more effective than either drug given alone.

Mortality and morbidity in patients with intermittent claudication in relation to the location of the occlusive atherosclerosis in the leg.

Mortality and morbidity from cerebrovascular and coronary arterial disease over a period of six years were studied in 224 non-diabetic patients with intermittent claudication. Patients with multiple arterial stenoses in the leg had a lower six-year survival than patients with single stenoses (55% versus 77%), with a higher mortality from cardiac deaths. These differences were still significant after adjustment for differences in clinical characteristics at the initial examination. This might indicate that patients with multiple arterial stenoses in the legs have a more widespread and more progressive atherosclerotic disease.

Raynaud's phenomenon in a female population: prevalence and association with other conditions.

In a random sample of 3000 women of ages eighteen to fifty-nine years in the city of Västerås, Sweden, 19% of the 2705 responders to a questionnaire complained of cold and white fingers with or without numbness. On the basis of interview and examination, 79% of these women were diagnosed as having Raynaud's phenomenon (RP), giving a prevalence of 15.6%. A significantly higher rate of family members with cold, white fingers was found only in the group of women with pronounced RP (p less than 0.001). A significantly higher frequency of women with pronounced RP than of the control group had a history of recurrent muscle/joint pain (p less than 0.05). Laboratory tests that might indicate an active connective tissue disease did not, however, confirm a diagnosis of rheumatoid arthritis. All three subgroups differed significantly from the control group in terms of recurrent chest pains; subgroups 2 and N differed significantly from controls in terms of recurrent headaches.

The concentration of magnesium in erythrocytes in female patients with primary Raynaud's phenomenon; fluctuation with the time of year.

The magnesium (Mg) concentration was measured in erythrocytes of 30 women with pronounced primary Raynaud's phenomenon (PRP) and of 33 age-matched healthy control women. The measurements were made at three different times, six months apart. The mean Mg concentration in the PRP group and the control group differed significantly at each measurement. The values for the two groups were, respectively, 1.64 +/- 0.21 and 2.02 +/- 0.21 mmol/L (P < 0.001) in February, 1988; 2.16 +/- 0.21 and 1.85 +/- 0.21 mmol/L (P < 0.001) in August, 1988; and 2.01 +/- 0.21 and 2.37 +/- 0.20 mmol/L (P < 0.001) in January, 1989. The erythrocyte Mg level varied significantly with the time of year in both groups. In the PRP group the mean value was significantly higher in August than in the two winter months, but in the control group it was significantly lower in August. The authors conclude that women with PRP have a significantly lower magnesium concentration in erythrocytes during winter than the healthy controls and that this concentration varied with the season of the year in both groups.

Effect of magnesium sulfate infusion on circulating levels of noradrenaline and neuropeptide-Y-like immunoreactivity in patients with primary Raynaud's phenomenon.

The effect of a short-term magnesium sulfate (MgSO4) infusion on venous plasma concentration of noradrenaline (NA) and neuropeptide-Y-like immunoreactivity (NPY-LI) was investigated in 12 women with primary Raynaud's phenomenon (PRP) and in 12 healthy matched controls. The Raynaud's patients did not demonstrate any significant changes in mean basal plasma NA concentration (0.29 +/- 0.15 vs 0.37 +/- 0.09 ng/mL, ns) after MgSO4 infusion. However, in the controls there was more than twice the amount of circulating noradrenaline (cNA) (0.21 +/- 0.14 vs 0.54 +/- 0.22 ng/mL, P < 0.001) after MgSO4 infusion, compared with the preinfusion value. Measurements during the cold pressor test prior to the MgSO4 infusion showed a significant increase of cNA in both the PRP group and the control group (from 0.29 +/- 0.15 to 0.33 +/- 0.16 ng/mL, P < 0.05, and from 0.21 +/- 0.14 to 0.29 +/- 0.16 ng/mL, P < 0.005, respectively). After MgSO4 infusion the levels of cNA during the cold pressor test increased significantly only in the PRP group (from 0.37 +/- 0.09 to 0.41 +/- 0.11 ng/mL, P < 0.05). Circulating NPY-LI concentrations increased significantly during MgSO4 infusion in the Raynaud's patients as well as in the controls from 105 +/- 21 to 127 +/- 23 pmol/L, P < 0.05, and from 107 +/- 17 to 132 +/- 27 pmol/L, P < 0.01, respectively. There were no detectable changes during the cold pressor tests in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

A prospective randomized study of a dental appliance compared with uvulopalatopharyngoplasty in the treatment of obstructive sleep apnoea.

The enthusiasm for uvulopalatopharyngoplasty (UPPP) in the treatment of obstructive sleep apnoea (OSA) has declined in recent years, partly because of a lower success rate over time and partly because of adverse effects. Reports on the beneficial effects of dental appliances exist, but only one prospective randomized study has been published comparing dental appliances with nasal continuous positive airway pressure (CPAP) treatment. No study has been published comparing dental appliance treatment with UPPP. Ninety-five male patients with confirmed OSA, subjective daytime sleepiness and an apnoea index (AI) > 5 were randomized for subsequent treatment with either a dental appliance or UPPP. There were 49 patients in the dental appliance group and 46 in the UPPP group. Thirty-seven patients in the dental appliance group and 43 in the UPPP group completed the 12-month follow-up. The success rate (rate of patients with at least a 50% reduction in AI) for the dental appliance group was 95%, which was significantly higher (p < 0.01) than the 70% success rate for the UPPP group. According to the criteria for OSA (apnoea index > or = 5 or apnoea/hypopnoea index > or = 10), 78% of the dental appliance group and 51% of the UPPP group were normalized after 12 months. The difference between the groups was significant (p < 0.05). These findings suggest that the dental appliance technique is useful in the treatment of mild to moderate OSA.

Thallium-201 myocardial imaging at rest in male orienteers and other endurance athletes.

During the period 1979 to 1992, 16 sudden unexpected cardiac deaths were known to have occurred in young Swedish orienteers. Autopsy indicated myocarditis to be the most frequent finding, most often combined with extensive myocardial fibrosis. The aim of the present investigation was to explore whether young male orienteers show a higher frequency than other young elite endurance athletes (controls) in the occurrence of Thallium-201 myocardial perfusion defects at rest, suggestive of fibrosis evoked by myocarditis. Thallium-201 perfusion abnormalities at rest were more frequently found in the controls than in the orienteers (26% vs. 12%, p=0.03). Uneven Tl-201 perfusion was associated with left ventricular mass (r=0.32, r=0.24, p<0.01, p=0.02) and body weight (r=0.30, r=0.31, p<0.01, p=0.03) in orienteers and controls, respectively. Echocardiographic left ventricular wall motion abnormalities were found in 11 athletes (9 orienteers and 2 controls) but only two displayed an abnormal Thallium-201 perfusion scan at rest. Perfusion abnormalities at rest did not occur more frequently in the orienteers but were commonly found in both groups of apparently healthy athletes making it futile to discern abnormals from normals. Thallium-201 perfusion aberrations were not associated with left ventricular wall motion abnormalities obtained by echocardiography.

Effects and adverse events of a dental appliance for treatment of obstructive sleep apnoea.

In a prospective study, 95 patients with mild to moderate obstructive sleep apnoea (OSA) were randomised to receive either surgical treatment, uvulopalatopharyngoplasty, (4-6 patients) or treatment with a nocturnal dental appliance for mandibular advancement (49 patients). Of the 49 dental appliance patients, 37 completed the 12-month follow-up. The aim of this study was to evaluate the effects and adverse events of dental appliance treatment from a one-year perspective. Somnography was employed to measure treatment effects before and 12 months post-treatment. At the 12-month control, somnography was performed twice: the first time with the dental appliance and the second time without it. Adverse events were recorded 2 weeks and 3, 6, and 12 months after treatment was initiated. The patients used the dental appliance on average 6 nights/week. After 12 months of treatment, the apnoea, apnoea/hypopnoea, oxygen desaturation, and snoring indices decreased significantly. Ninety-five per cent of the patients reduced their apnoea index by > or = 50% and 78% of the patients were normalised following treatment. At the somnographic registration without the dental appliance, the values were found comparable to what they were before treatment. Mandibular mobility and occlusion were constant throughout the study. The adverse events resulting from using the dental appliance were relatively minor and infrequent, and no serious complications were observed except for two patients who reported pain from the temporomandibular joint. In conclusion, the dental appliance has been shown to be a valuable treatment method for mild to moderate OSA with few adverse events in the stomatognathic system or other complications.

[How to manage all those ECGs? Experiences with computer-based storage and interpretation of electrocardiograms in the county of Vastmanland]. / Hur hantera alla EKG? Erfarenheter från datoriserad lagring och tolkning av EKG i Västmanland.

We describe our experience using a database (Sicare, Siemens Elema) containing 381,000 ECGs covering 90% of all ECGs during 11 years in the county of Västmanland, Sweden, with 260,000 inhabitants. The database expedites rapid recovery of earlier ECGs. For instance, in patients admitted to coronary care with chest pain and ST-elevation, speedy access to an earlier ECG with identical ST-elevation may be crucial for avoiding unnecessary and potentially harmful thrombolysis. The database also enables us to select ECGs with a specific diagnosis, for instance atrial fibrillation. This facilitates characterization and quality control of treatment of atrial fibrillation in a well-defined population.

[Comparison of the cumulative survival among patient groups with a left main coronary artery lesion after surgical and therapeutic treatment]. / Sravnenie sovokupnoi vyzhivaemosti sredi grupp patsientov s porazheniem glavnogo stvola levoi koronarnoi arterii posle operativnogo i terapevticheskogo lecheniia.

In order to evaluate survival patterns in patients with left main coronary artery (LMCA) disease, 1492 patients with LMCA disease admitted to the U. S. Collaborative Study on Coronary Artery Surgery (CASS) were followed up. Of the 1492 patients, 1183 (79%) underwent coronary artery bypass (CABG) with an operative mortality of 4.2% and an average of 2.7 grafts/patient inserted. Allocation to surgery was by patient and physician preference and not random. Surgical patients generally had more severe angina, a higher prevalence of beta blocker usage, worse ventricular function and more severe LMCA stenosis than medically treated patients. Overall (4 years) survival of the surgical group was 88% compared to 63% in the medical group (p less than 0.001). Other independent predictors of mortality included angiographic left ventricular (LV) dysfunction score, age, % LMCA stenosis, hypertension, dominance, and presence of significant right coronary artery (RCA) stenosis greater than or equal to 50%. CABG was not shown to significantly improve survival in women, in LMCA patients with left dominant circulation, in LMCA patients with non-diseases dominant or balanced RCA circulation or in LMCA patients with greater than or equal to 50% RCA stenosis but good LV function. These data indicate that CABG prolongs life in most patients with left main coronary artery disease, particularly those with severe LMCA narrowing or severe LV dysfunction, however, subgroups of LMCA patients are identifiable who may fare with medical treatment alone.