Left main coronary artery stenosis: the influence of aortocoronary bypass surgery on survival

Prognostic value of early left ventricular ejection fraction reserve during regadenoson stress solid-state SPECT-MPI

BACKGROUND

We hypothesized early post-stress left ventricular ejection fraction reserve (EFR) on solid-state-SPECT is associated with major cardiac adverse events (MACE).

METHODS

151 patients (70 ± 12 years, male 50%) undergoing same-day rest/regadenoson stress 99mTc-sestamibi solid-state SPECT were followed for MACE. Rest imaging was performed in the upright and supine positions. Early stress imaging was started 2 minutes after the regadenoson injection in the supine position and followed by late stress acquisition in the upright position. Total perfusion deficit (TPD) and functional parameters were quantified automatically. EFR, ∆end-diastolic volume (EDV), and end-systolic volume (ESV) were calculated as the difference between stress and rest values in the same position. EFR < 0%, ∆EDV ≥ 5 ml, or ∆ESV ≥ 5 ml was defined as abnormal.

RESULTS

During the follow-up (mean 3.2 years), 28 MACE occurred (19%). In Kaplan-Meier analysis, there was a significantly decreased event-free survival in patients with early EFR < 0% (P = 0.004). Similarly, there was a decreased event-free survival in patients with ∆ESV ≥ 5 ml at early stress (P = 0.003). However, EFR, ∆EDV, and ∆ESV at late stress were not associated with MACE-free survival. Cox proportional hazards model adjusting for clinical information and stress TPD demonstrated that EFR, ∆EDV, and ∆ESV at early stress were significantly associated with MACE (P < 0.05 for all).

CONCLUSIONS

Reduced early post-stress EFR on vasodilator stress solid-state SPECT is associated with MACE.

Long-Term Outcomes of Unprotected Left Main Percutaneous Coronary Intervention in Centers Without Onsite Cardiac Surgery

Unprotected left main (LM) percutaneous coronary intervention (PCI) at centers without onsite cardiac surgery remains controversial. We aimed to evaluate the effect of onsite cardiac surgery on short-term and long-term outcomes in patients who had unprotected LM PCI. We analyzed Victorian Cardiac Outcomes Registry data on consecutive patients who had unprotected LM PCI at cardiac surgical centers (SCs) and non-SCs (NSCs) between January 2014 to December 2018. Compared with the SC group (n = 594, 81%), the NSC group (n = 136) were younger (69 vs 72 years) and presented with more ST-elevation myocardial infarction (35% vs 16%) and cardiogenic shock (25% vs 15%), with higher rates of preprocedural intubation (17% vs 11%) and mechanical circulatory support (20% vs 9.3%), all p <0.01. Unadjusted in-hospital mortality (23% vs 11.4%), and 30-day major adverse cardiac events (composite of mortality, myocardial infarction, stent thrombosis, or unplanned revascularization) (26% vs 16%) were higher in NSC patients, all p <0.01. However, following multivariable adjustment, SC was neither a predictor of in-hospital mortality (odds ratio 0.68, 95% confidence interval [CI] 0.32 to 1.43, p = 0.31), 30-day mortality (odds ratio 0.70, 95% CI 0.33 to 1.48, p = 0.35) nor long-term survival at 60 months (hazard ratio 0.88, 95% CI 0.62 to 1.27, p = 0.51). Propensity score analysis confirmed the neutral effect of onsite cardiac surgery on long-term survival (hazard ratio 0.99, 95% CI 0.66 to 1.50, p = 0.97). In conclusion, patients who underwent unprotected LM PCI at NSCs presented with greater acuity of illness. Despite this, the availability of onsite cardiac surgical support was not associated with in-hospital, 30-day, or long-term outcomes underscoring the safety of LM PCI in NSCs.

Total Occlusion of the Left Main Coronary Artery

An extremely rare case with total occlusion of the left main coronary artery is described. The role of collaterals from the right coronary artery in the maintenance of adequate left ventricular function and in the patient's survival is discussed. The need for emergency aortocoronary bypass surgery, once the lesion is discovered, is stressed. An excellent clinical result of aortocoronary bypass surgery in a patient followed for more than 2 years with a usually fatal condition is shown.

Unprotected Left Main Disease: Indications and Optimal Strategies for Percutaneous Intervention

OPINION STATEMENT

Although the incidence of left main (LM) coronary artery disease is relatively low in patients undergoing routine angiography, it is a common presentation in patients with acute coronary syndromes. With the current interventional tools and techniques, percutaneous intervention for LM disease has become a viable alternative to the traditional coronary artery bypass grafting. Factors that contribute to the success and appropriateness of percutaneous intervention for LM disease include coronary anatomy and patient-specific factors such as left ventricular function. Multiple considerations should be taken into account prior to intervention, including hemodynamic support if necessary, intravascular imaging to guide therapy, and stent technique. This review provides an overview of the current body of literature to support the use of percutaneous intervention in LM disease and serves as guideline for the interventionalist approaching LM revascularization.

Similar survival 15 years after coronary artery surgery irrespective of left main stem stenosis

OBJECTIVES

To evaluate 15-year survival after coronary artery bypass grafting (CABG) in relation to grade left main stenosis (LMS) and right coronary artery (RCA) obstruction.

DESIGN

Coronary angiographic findings were prospectively collected in 977 patients who had CABG for stable angina during 1994-1995 and were included in the Swedish Coronary Revascularization - Swedish Council of Technology Assessment study.

RESULTS

Significant LMS was present in one fifth of the patients and significant RCA obstruction was found in 61% of those with LMS and in 68% of patients without LMS. The patients were categorized as no LMS (Group I), LMS without RCA obstruction (Group II) or significant LMS with significant right coronary artery (RCA) obstruction (Group III). Early mortality did not differ in the three groups and was 1.2, 1.2% and 0.8% in group I, II and III, respectively. Corresponding survival at 15 years was similar 51%, 47% and 47%, respectively. In multivariable analysis older age, smoking, severe angina, positive stress test, hypertension, diabetes mellitus and ejection fraction < 50% were risk factors for death at 15 years.

CONCLUSIONS

Death 15 years after CABG correlated to clinical variables but was not predicted from presence of LMS with or without significant associated RCA obstruction.

Stenting of complex lesions: an overview

Contemporary management of coronary artery disease relies increasingly on percutaneous techniques combined with medical therapy. Although percutaneous coronary intervention (PCI) can be performed successfully in most lesions, several difficult lesion subsets continue to present unique technical challenges. These complex lesions may be classified according to anatomic criteria, including extensive calcification, thrombus, and chronic occlusions, or by location, such as bifurcations, saphenous vein grafts and unprotected left main. PCI of these lesions often requires novel devices, such as drug-eluting stents, hydrophilic guidewires, distal protection balloons or filters, thrombectomy catheters, rotational atherectomy, and cutting balloons. An integrated approach that combines these devices with specialized techniques and adjunctive pharmacologic agents has greatly improved PCI success rates for these complex lesions.

Single-photon emission computed tomography myocardial perfusion imaging in the diagnosis of left main disease

BACKGROUND

Left main disease (LMD), defined as > or = 50% lesion stenosis, occurs in 3% to 5% of patients undergoing catheterization. Limited data on the value of single-photon emission computed tomography (SPECT) imaging for diagnosis of LMD exists.

HYPOTHESIS

This study sought to evaluate the diagnostic accuracy of SPECT imaging in the diagnosis of LMD.

METHODS

A total of 74 consecutive patients with LMD, identified from our catheterization lab database (January 2003-December 2007) with gated exercise (15 patients) or adenosine (59 patients), thallium 201, or Tc-99m SPECT imaging within 6 months of index angiography were included. Group 1 (Gp 1) included 33 patients with isolated LMD. Group 2 (Gp 2) consisted of 41 patients with LMD and 1-vessel disease (6); LMD and 2-vessel disease (24); and LMD and 3-vessel disease (11).

RESULTS

Reversible perfusion defects (PD) were absent in 6 (18%) of Gp 1 and 8 (20%) of Gp 2 patients. Among Gp 1 patients, PD in 1-vessel, 2-vessel, 3-vessel distribution were seen in 20 (61%), 5 (15%), and 2 (6%) patients respectively. In comparison, PD in 1-vessel, 2-vessel, 3-vessel distribution were observed in 20 (49%), 12 (29%), and 1 (2%) of Gp 2 patients respectively. Left main (LM) pattern was noted in 6 patients (Gp 1: 2, Gp 2: 4). Transient ischemic dilatation (TID) was encountered in 34 patients (Gp 1: 17, Gp 2: 17) and in 4 patients with normal perfusion scans.

CONCLUSIONS

These data represent the largest analysis of patients with "isolated" LMD. Approximately 19% of patients with LMD have no reversible PD on SPECT. While LM pattern is rare, 1-vessel distribution PD and TID represent the most frequent SPECT abnormalities.

Can left main or proximal left anterior descending coronary artery disease be assessed by non-invasive means?

One hundred consecutive patients with angina pectoris referred for coronary arteriography were studied prospectively for non-invasive assessment of left main (LMCA) or proximal left anterior descending coronary artery (proximal LAD) disease. Evaluation of echocardiographic interventricular septal motion, history and exercise test response could not identify the patients with these specific lesions. It is concluded that LMCA and proximal LAD disease still remain largely unpredictable by non-invasive means.

Important parameters in the detection of left main trunk disease using stress myocardial perfusion imaging

OBJECTIVES

We sought noninvasively to diagnose left main trunk (LMT) disease using myocardial perfusion imaging (MPI).

METHODS

Five hundred and eight patients with suspected coronary artery disease (CAD) underwent both stress MPI and coronary angiography. The extent and severity of perfusion abnormalities were assessed using a 20-segment model. In addition, perfusion defects in both left anterior descending and left circumflex arterial territories were defined as a left main (LM) pattern defect, and those in 3-coronary arterial territories as a 3-vessel pattern defect.

RESULTS

In 42 patients with LMT disease, a summed stress score (19.4 ± 10.0 vs. 13.5 ± 10.0; p < 0.0001) and a summed rest score (12.1 ± 9.7 vs. 7.0 ± 7.8; p = 0.002) were greater than in 466 patients without LMT disease, while a summed difference score was similar (7.3 ± 7.7 vs. 6.5 ± 6.1; p = NS). The prevalence of an LM-pattern defect was low in both groups (12% vs. 8%; p = NS). However, a 3-vessel pattern defect (33% vs. 7%; p < 0.0001), lung uptake of radiotracers (38% vs. 11%; p < 0.0001), and transient ischemic dilation (31% vs. 13%; p = 0.003) were more frequently observed in patients with LMT disease than in those without. Logistic regression analysis showed that a 3-vessel pattern defect (OR=3.5, 95% CI = 1.4-8.8; p = 0.007), lung uptake of radiotracers (OR = 2.5, 95% CI = 1.1-5.7; p = 0.03), and previous myocardial infarction (MI) (OR = 2.4, 95% CI = 1.0-5.7; p = 0.05) were the most important parameters to detect LMT disease. After excluding 163 patients with previous MI, a repeat analysis revealed that lung uptake of radiotracers (OR = 8.2, 95% CI = 2.3-29.2; p = 0.001) and an LM-pattern defect (OR = 6.3, 95% CI = 1.4-27.2; p < 0.02) were independent predictors for LMT disease.

CONCLUSION

In the identification of LMT disease, lung uptake of radiotracers was a single best parameter, which was independent of the presence or absence of previous MI.

Underestimation of extent of ischemia by gated SPECT myocardial perfusion imaging in patients with left main coronary artery disease

BACKGROUND

There have been limited data regarding the value of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the detection of left main coronary artery disease (CAD).

METHODS AND RESULTS

We studied 101 patients with angiographic left main CAD (> or = 50% stenosis) and no prior myocardial infarction or coronary revascularization who underwent gated exercise or adenosine stress technetium 99m sestamibi SPECT MPI. By perfusion assessment alone, high-risk disease with moderate to severe defects (> 10% myocardium at stress) was identified in only 56% of patients visually and 59% quantitatively. Absence of significant perfusion defect (> or = 5% myocardium) was seen in 13% of patients visually and 15% quantitatively. However, by combining visual perfusion data and nonperfusion variables, especially transient ischemic dilation, 83% of patients were identified as high risk.

CONCLUSIONS

The findings of this study demonstrate that assessment of perfusion data alone by visual or quantitative SPECT MPI analysis underestimates the magnitude of left main CAD. The combination of perfusion and nonperfusion abnormalities on gated MPI identifies high risk in most patients with left main CAD.

How good are experienced interventional cardiologists at predicting the functional significance of intermediate or equivocal left main coronary artery stenoses?

BACKGROUND

Decisions for coronary revascularisation are frequently based on visual assessment of the severity of a stenosis. In patients with intermediate left main stem lesions clinical decision making based on FFR is safe and feasible. This study was performed to assess the accuracy of visual angiographic assessment of intermediate or equivocal left main coronary artery (LMCA) stenoses by experienced interventional cardiologists when taking fractional flow reserve (FFR) measurements as the gold standard.

METHODS

Fifty-one patients with intermediate (40-80% diameter stenosis by angiography) or equivocal LMCA disease were evaluated by FFR. Angiograms were then reviewed by 4 experienced interventionalists from different university hospitals blinded to FFR results. Lesions were visually assessed and their significance classified as 'significant', 'not significant', or 'unsure' if the observer was unable to make a decision regarding lesion significance based on the angiogram.

RESULTS

Results were compared with two different FFR cutoff values (< 0.75 and < or = 0.80) for hemodynamic significance. The 4 reviewers achieved correct lesion classification in no more than approximately 50% of cases each, regardless of FFR threshold. The interobserver agreement between two reviewers in excess of the agreement expected due to chance was outperformed on average by only 16%. Furthermore, interobserver variability was large resulting in unanimously correct lesion classification in only 29% of all cases.

CONCLUSIONS

The functional significance of intermediate and equivocal LMCA stenoses should not be based solely on angiographic assessment even by experienced interventional cardiologists.

The impact of cardiovascular risk factors on subclinical left main coronary artery disease: an intravascular ultrasound study

BACKGROUND

The impact of cardiovascular risk factors on subclinical but measurable left main coronary artery (LMCA) atherosclerosis is not well known.

METHODS

We analyzed 150 consecutive patients with first-time coronary artery disease presentation undergoing intervention of a left anterior descending coronary artery or left circumflex lesion with motorized intravascular ultrasound transducer pullback that included a nonstenotic LMCA. Framingham, PROCAM, and European SCORE risk assessments were determined in 107 patients <65 years of age (because the Framingham, PROCAM, and European SCORE studies excluded patients >65 years old). Intravascular ultrasound measurements were compared in patients with <10% vs 10% to 20% risk of events.

RESULTS

Plaque volumes were greater in patients with higher risk scores: P = .007 in patients with 10% to 20% PROCAM risk, P = .063 in patients with 10% to 20% Framingham risk, and P = .059 in patients with 10% to 20% SCORE risk (P = .059). The mean arc of LMCA calcium (12 degrees +/- 25 degrees overall) correlated with plaque volume (51 +/- 28 mm3, r = 0.30, P = .0001) and with the number of coronary risk factors (P = .048) and ranged from 0.28 degrees +/- 0.74 degrees in patients with 0 to 1 risk factors to 9.95 degrees +/- 21.55 degrees in patients with 2 to 4 risk factors to 19.38 degrees +/- 32.51 degrees in patients with 5 to 7 risk factors. Regression analysis showed obesity and age were the most important factors contributing to LMCA calcium.

CONCLUSION

Intravascular ultrasound measurable atherosclerosis in nonstenotic LMCA correlates with conventional primary coronary risk scores. Left main coronary artery calcium correlates both with LMCA plaque volume and risk factors. Thus, subclinical LMCA atherosclerosis may be a marker for events that are predicted by commonly used primary risk-assessment algorithms.

Clinical outcome in patients with intermediate or equivocal left main coronary artery disease after deferral of surgical revascularization on the basis of fractional flow reserve measurements

BACKGROUND

Correct assessment of the significance of left main stem lesions is of pivotal importance to the patient with coronary artery disease. On the basis of clinical and angiographic information alone, this evaluation often cannot be done reliably. Limited data suggest that coronary pressure-derived fractional flow reserve (FFR) supports decision making in equivocal left main disease.

METHODS

All patients presenting to our institution between June 1999 and June 2004 with intermediate left main coronary artery disease (40%-80% diameter stenosis by angiography), or in whom left main coronary disease was suspected but could not be quantified angiographically, were included in this prospective single-center follow-up study. If FFR was <0.75 along the left main stem, surgical revascularization was recommended; if FFR was >0.80, medical treatment or percutaneous coronary intervention elsewhere in the coronary tree was chosen. If FFR was in the "gray zone," between > or = 0.75 and < or = 0.80 treatment recommendation was dependent on additional individual criteria. Primary end points were freedom from death, myocardial infarction, any coronary revascularization procedure, and stroke.

RESULTS

Fifty-one patients (mean age 62.2 +/- 9.6 years, 41 male) were included. In 27 patients (53%), coronary artery bypass surgery was performed. The remaining 24 patients (47%) were treated nonsurgically. Mean follow-up was 29 +/- 16 months. Estimated survival after 4 years of follow-up was 81% among patients in the surgical group and 100% among patients in the nonsurgical group. Event-free survival was 66% in the surgical group and 69% in the nonsurgical group.

CONCLUSIONS

Fractional flow reserve is helpful to identify patients with intermediate left main disease in whom deferral of surgical revascularization is associated with excellent survival and low event rates.

Les facteurs cliniques et opératoires associés à la mortalité hospitalière après chirurgie d’une sténose du tronc commun de l’artère coronaire gauche

Stenosis of left main coronary artery (LMCA) is a common finding on coronary angiographies (7 to 10%). Mortality is very high for conservative therapy in comparison with surgery, which provides very good long-term outcome and is accepted as the standard therapy of this condition. Over the last few years, percutaneous coronary intervention (PCI) has become a new alternative in selected patients.

AIM OF THE STUDY

To assess in hospital mortality in subjects referred to our surgical unit for coronary artery bypass grafting (CABG) and to identify the main clinical and surgical determinants of in-hospital mortality.

METHODS

Two year retrospective analysis (1998-1999) of in-hospital mortality and morbidity of patients having left main stenosis referred for CABG.

RESULTS

Among a group of 1443 patients operated for coronary heart disease, LMCA stenosis was found in 330 patients (22.9%). The mean age was 63 +/- 8.6 years. Elective surgery was done in 173 patients (52.4%), and acute operation (i.e. urgent, emergent or desperate) in 157 patients (47.6%). The total in-hospital mortality was 4.2% (14/330). Elective surgery in-hospital mortality was 1.7% (3/173) and urgent surgery in-hospital mortality was 7% (11/157). The main risk factors of in-hospital mortality were age > 68 years, low ejection fraction (LVEF<0.4), history of myocardial infarction, gender (female) and urgency of the operation.

CONCLUSION

The proportion of patients undergoing CABG for left main stenosis is relatively high in our center and their mortality is quite low especially for elective operations. As the mortality of patients treated by PCI for LMCA stenosis is similar to surgery in high-risk patients, we postulate that this approach can be a real alternative treatment for such patients. Because of its potential benefit, combined revascularisation is also an alternative that should be considered in some cases. Furthermore, as a new generation of coated stents has emerged in the treatment of restenosis after PCI, we hypothesize that this method can in the near future be accepted as equivalent to surgery. However several randomized clinical trials must first be conduced prove this point.

Isolated left main coronary artery stenosis: long term follow up in 106 patients after surgery

OBJECTIVE

To analyse the long term prognosis in patients with isolated stenoses of the left main coronary artery (LMCA) following surgical revascularisation.

PATIENTS

106 patients (71 men and 35 women, mean age 61 years) were operated on between 1982 and 1998. Before surgery, 103 patients presented with angina pectoris and only 10 had a history of myocardial infarction. Their mean left ventricular ejection fraction was 62%. Stenoses were localised on the LMCA ostium in 19 patients, a subgroup characterised by a high proportion of women (68%). Three patients presented with chronic LMCA occlusion. Forty six patients were operated on as an emergency. The mean (SD) number of grafts per patient was 2.0 (0.5), and only one patient had no left anterior descending (LAD) coronary artery bypass. Bypass of the LAD using the internal thoracic artery was performed in 88 cases.

RESULTS

Early postoperative mortality was 4.7% and the five year survival was 86.8%. Late mortality occurred in nine cases, and in three of these it was linked to a coronary condition. Of the 92 long term survivors, 81.5% were totally symptom-free and 77% of those of working age were able to resume work. The postoperative outcome of patients with isolated ostial LMCA stenosis did not differ significantly from that of the other patients.

CONCLUSIONS

The postoperative prognosis of isolated LMCA stenosis appears good in terms of mortality and symptoms.

Percutaneous reperfusion of left main coronary disease complicated by acute myocardial infarction

Previous studies have shown a benefit of a strategy of direct angioplasty and stenting in patients with acute myocardial infarction (AMI) complicated by early cardiogenic shock. However, few data exist for the subset of patients with left main trunk disease complicated by AMI and cardiogenic shock. We performed an analysis of patients with AMI who underwent mechanical intervention between January 1995 and December 2000. Out of 1,433 patients with ST segment elevation AMI treated with primary coronary angioplasty (PTCA), 22 patients (1.5%) had left main disease (LMD) as the culprit lesion. Baseline characteristics were age, 66 +/- 11 years; female gender, 9%; diabetes, 14%; previous myocardial infarction, 14%; mean systolic blood pressure, 77 +/- 24 mm Hg; time to treatment, 4.8 +/- 2.2 hr; TIMI 0-1, 77%; collateral flow (Rentrop grade >or= 2) 9%. The primary success rate was 91%. Primary stenting was performed in 17 patients (77%). The in-hospital mortality rate was 50%. All deaths were due to refractory shock. The 6-month survival rate was 41% +/- 1%, while the event-free survival rate was 27% +/- 10%. At 6-month follow-up, the mortality rate increased to 59%; the target vessel revascularization rate was 14%. A percutaneous mechanical intervention strategy in patients with left main disease complicated by AMI is feasible and effective, and patients discharged alive have a good mid-term prognosis.

Unprotected left main coronary artery stenting: correlates of midterm survival and impact of patient selection

BACKGROUND

The study served to present the in-hospital and six-month clinical outcome and also the long-term survival data of a consecutive series of patients undergoing stenting for unprotected left main coronary artery (LMCA) disease.

METHODS

Revascularization with coronary bypass surgery has been generally recommended for treatment of left main coronary stenosis. Improvements in angioplasty and coronary stent techniques and equipment may result in the wider applicability of a percutaneous approach. A total of 92 consecutive patients underwent unprotected LMCA stenting between March 1994 and December 1998. For the initial 39 patients (group I) angioplasty was performed only when surgical revascularization was contraindicated. The remaining 53 patients (group II) also included patients in whom surgery was feasible. Patients were followed for 7.3 +/- 5.8 months (median 239 days; range 49 to 1,477 days).

RESULTS

Compared to group I, group II patients had higher left ventricular ejection fraction (60 +/- 12% vs. 51 +/- 16%, p < 0.01), less severe LMCA stenosis (68 +/- 12% vs. 80 +/- 10%, p < 0.001), lower surgical risk score (13 +/- 7 vs. 20 +/- 7, p < 0.001), and had angioplasty more often performed via the radial approach (88% vs. 23%, p < 0.001) with smaller guiding catheters (6F: 49% vs. 15%; 8F: 2% vs. 77%, p < 0.001). The procedural success rate was 100%. In-hospital mortality was 4% (4 deaths, 3 cardiac). During follow-up there were six deaths, 13 patients required repeat percutaneous transluminal coronary angioplasty (4 LMCA), and two required coronary artery bypass graft surgery. Estimated survival (+/- SEE) was 89 +/- 6.3% at 500 days and 85 +/- 12% at 1,000 days post-stenting. Overall mortality was 3.8% in group II and 20.5% in group I (p < 0.02).

CONCLUSIONS

Coronary stenting can be performed safely in high-risk individuals with acceptable intermediate-term outcome. It may be feasible to broaden the application of this technique in selected patients needing revascularization for left main coronary disease.

Improved detection of left main coronary artery disease with attenuation-corrected SPECT

BACKGROUND

Myocardial perfusion imaging has demonstrated a limited sensitivity as a means of accurately identifying left main (LM) coronary disease. Because regional quantitative perfusion biases are eliminated with attenuation corrected (AC) single photon emission computed tomography (SPECT), as compared with uncorrected (NC) SPECT, we hypothesized that AC SPECT would demonstrate increased diagnostic accuracy for the detection of significant LM coronary stenosis.

METHODS AND RESULTS

We studied 28 patients (23 men, 5 women; mean age, 66+/-9 years) with significant LM stenoses (> or =50%) and 34 control patients (27 men, 7 women; mean age, 65+/-11 years) with 2-vessel coronary disease. Rest thallium-201 and stress technetium 99m sestamibi SPECT imaging with and without AC were performed, as described earlier. Both AC and NC images were analyzed visually and quantitatively in comparison with corresponding normal databases. A greater sensitivity for detection of an LM defect pattern (64% vs. 7%, P = .0009) with equivalent specificity (94% vs. 100%, P = not significant) was demonstrated by means of visual analysis of AC SPECT images. More disease was demonstrated in a greater number of territories with AC SPECT images than with NC images (2.14+/-0.97 for AC images vs. 1.43+/-0.84 for NC images, P = .0001). Similar improvement in the detection of LM disease was shown by means of automated quantitative analysis (57% for AC SPECT vs 14% for NC SPECT, P = .0005), again with no loss in specificity.

CONCLUSIONS

AC SPECT with the University of Michigan method in consecutive patients with LM stenoses and a select control population with severity matched multivessel coronary disease significantly improved the diagnostic accuracy of myocardial perfusion imaging for the identification of LM coronary disease, compared with uncorrected SPECT.

One-year follow-up after intravascular ultrasound assessment of moderate left main coronary artery disease in patients with ambiguous angiograms

OBJECTIVES

The purpose of this study was to correlate angiographic and intravascular ultrasound (IVUS) findings in left main coronary artery (LMCA) disease and identify the predictors of coronary events at one year in patients with LMCA stenoses.

BACKGROUND

Significant (> or =50% diameter stenosis [DS]) LMCA disease has a poor long-term prognosis.

METHODS

One hundred twenty-two patients who underwent angiographic and IVUS assessment of the severity of LMCA disease and who did not have subsequent catheter or surgical intervention were followed for one year. Standard clinical, angiographic and IVUS parameters were collected.

RESULTS

The quantitative coronary angiography (QCA) reference diameter (3.91 +/- 0.76 mm, mean +/- 1 SD) correlated moderately with IVUS (4.25 +/- 0.78 mm, r = 0.492, p = 0.0001). The lesion site minimum lumen diameter (MLD) (2.26 +/- 0.82 mm) by QCA correlated less well with IVUS (2.8 +/- 0.82 mm, r = 0.364, p = 0.0005). The QCA DS measured 42 +/- 16%. During the follow-up period, 4 patients died, none had a myocardial infarction, 3 underwent catheter-based LMCA intervention and 11 underwent bypass surgery. Univariate predictors of events (p < 0.05) were diabetes, presence of another lesion whether treated with catheter-based intervention or untreated with DS > 50% and IVUS reference plaque burden and lesion lumen area, maximum lumen diameter, MLD, plaque area and area stenosis. Using logistic regression analysis diabetes mellitus, an untreated vessel (with a DS > 50%) and IVUS MLD were independent predictors of cardiac events.

CONCLUSIONS

In selected patients assessed by IVUS, moderate LMCA disease had a one-year event rate of only 14%. Intravascular ultrasound MLD was the most important quantitative predictor of cardiac events. For any given MLD, the event rate was exaggerated in the presence of diabetes or another untreated lesion (>50% DS).

Results of stenting of unprotected left main coronary artery stenosis in patients at high surgical risk

From March 1994 to September 1996, 39 patients underwent stenting of the unprotected left main coronary artery because of high surgical risk. Stenting appeared to improve clinical outcome, but there was a significant mortality rate at long-term follow-up.

Impact of stents on clinical outcomes in percutaneous left main coronary artery revascularization

Despite effective treatment of left main coronary artery (LMCA) disease by coronary bypass, there is still need for treatment of the LMCA due to progression of disease or bypass graft failure. We compared the in-hospital and follow-up (1-year) outcomes of patients with LMCA stenosis treated with stents (n = 88), with a matched group of patients undergoing LMCA non-stent procedures (n = 36). Ninety-seven percent of patients in each group underwent previous coronary bypass. Procedural success (angiographic success without major in-hospital complications) tended to be higher in stent patients than in their non-stent counterparts (98% vs 92%, p = 0.12), and overall procedural complications were higher for the non-stent group (5.4% vs 0%, p = 0.03). The incidence of non-Q-wave myocardial infarction was higher in patients with the LMCA treated with stents than in non-stent patients (13% vs 2.7%, p = 0.09). There was no difference in death or Q-wave myocardial infarction between the 2 groups during follow-up. Overall target lesion revascularization at 1 year was 15% after LMCA stenting, and 18% in non-stent patients (p = 0.71). Also, any cardiac event-free survival (including death, Q-wave myocardial infarction, coronary bypass, or angioplasty) was similar for both groups (78% for stents vs 76% for non-stents, p = 0.85). We conclude that in patients undergoing LMCA interventions, stents reduce major hospital complications, but may not significantly reduce repeat revascularization or major cardiac events at 1 year compared with non-stent LMCA procedures.

Percutaneous treatment of protected and unprotected left main coronary stenoses with new devices: immediate angiographic results and intermediate-term follow-up

OBJECTIVES

We sought to evaluate the immediate angiographic results and intermediate-term follow-up after percutaneous treatment of left main coronary stenoses in the new device era.

BACKGROUND

Historically, balloon angioplasty of left main coronary stenoses has been associated with high procedural morbidity and poor long-term results. It is not clear whether new devices are more effective in this anatomic setting.

METHODS

Between July 1993 and July 1995, we performed initial left main coronary interventions on 46 patients (mean age 67 +/- 12 years, 26% women). Quantitative angiography was available for 42 of 46 interventions, and clinical follow-up was obtained for all patients at 1 month, 6 months and 1 year after initial revascularization.

RESULTS

Most interventions (42 of 46) were performed in patients with "protected" coronary stenoses to the left coronary system owing to the presence of one or more patent left main coronary grafts. Seventy-seven percent of screened patients were deemed unsuitable for repeat coronary artery bypass surgery. Procedures performed included stenting in 73% of patients (alone in 30% and after rotational atherectomy in 43%), rotational atherectomy in 58% (alone in 15% and before stenting in 43%), directional atherectomy in 4% and angioplasty alone in 7%. Initial procedural success was achieved in all interventions, with no deaths, myocardial infarctions (creatine kinase, MB fraction > 50 IU/liter) or emergent bypass surgery. Follow-up data to date (median duration 9 months, range 6 to 19) demonstrate a 98% overall survival rate and a 6-month event-free survival rate of 78% (six target vessel revascularizations [TVRs], four non-TVRs).

CONCLUSIONS

Treatment of protected left main coronary artery stenoses can be accomplished safely and effectively with new device technology. Intermediate-term follow-up demonstrates an acceptably low rate of death, myocardial infarction or repeat revascularization at 6 months and 1 year.

Comparison of ischemic response during exercise and dobutamine echocardiography in patients with left main coronary artery disease

OBJECTIVES

This study sought to compare manifestations of myocardial ischemia evoked by exercise and dobutamine echocardiography in patients with left main coronary artery disease.

BACKGROUND

During exercise testing, left ventricular cavity dilation, marked ST segment depression and blood pressure decrease indicate severe coronary artery disease. Whether these signs are comparably evoked by dobutamine echocardiography has not been described.

METHODS

Fifty-four patients who underwent stress echocardiography (36 exercise, 18 dobutamine) and coronary angiography showing > or = 50% left main stenosis were analyzed. Electrocardiographic and blood pressure changes, symptoms, wall motion score indexes and sensitivity for coronary artery disease were compared. In 47 patients, the left ventricular endocardium was traced to quantify volumes and ejection fraction.

RESULTS

Stress-induced regional wall motion abnormalities developed in 91% of patients; this was not different on exercise (89%) or dobutamine echocardiography (94%). Rate-pressure product and wall motion score index, similar at rest, tended to be higher after exercise than after dobutamine stress (p = 0.07 and p = 0.05, respectively). ST segment depression > or = 1 mm was more common with exercise (p = 0.005). Ejection fraction and end-systolic and end-diastolic volume indexes were comparable at rest in both groups. With exercise, ejection fraction decreased in 87% of patients, and end-systolic and end-diastolic volume indexes increased in 80%. In contrast, with dobutamine, decreased ejection fraction and increased volume indexes were infrequent. Ejection fraction was lower ([mean +/- SD] 45 +/- 19% vs. 54 +/- 12%, p = 0.007) and end-diastolic (69 +/- 26 vs. 50 +/- 17 ml/m2, p =0.02) and end-systolic (39 +/- 20 vs. 24 +/- 13 ml/m2, p = 0.02) volume indexes were higher after exercise than after dobutamine stress.

CONCLUSIONS

On the basis of changes in regional wall motion both dobutamine and exercise echocardiography have a comparable high sensitivity in diagnosing myocardial ischemia in left main coronary artery disease. However, conventional signs of severe myocardial ischemia, including left ventricular cavity dilation and marked ST segment depression, occur more often with exercise than with dobutamine echocardiography.

Can patients with left main stenosis wait for coronary artery bypass grafting?

BACKGROUND

The economic impact of health care reforms may result in waiting lists for coronary artery bypass grafting. This study was designed to examine the clinical results of patients with left main stenosis who were placed on a triaged wait list for operation.

METHODS

Data were collected prospectively on 2,145 patients undergoing isolated coronary artery bypass grafting between 1989 and 1994. Critical left main stenosis (LMS, 50% or more stenosis) was present in 281 patients, and 1,864 patients had no left main disease, or a left main stenosis of less than 50% (no LMS).

RESULTS

The average time from angiography to operation was shorter in patients with LMS (LMS 38 +/- 46 days versus no LMS 84 +/- 71 days; p = 0.0001). Two patients in the LMS group died; they had declined operation. Four patients suffered non-Q wave myocardial infarctions, all of whom subsequently underwent operation with no perioperative complications. The presence of LMS did not influence operative mortality (LMS 2.8% versus no LMS 1.3%), the incidence of low output syndrome (LMS 8.3% versus no LMS 5.4%), or the incidence of perioperative myocardial infarction (LMS 3.8% versus no LMS 4.2%). To examine the effect of waiting time on outcomes, patients with LMS were divided into early (operation 10 days or less after angiography) and late revascularization groups (more than 10 days). Operative mortality, low output syndrome, and myocardial infarction were similar in the early and late groups. Patients in the early group were more likely to have New York Heart Association functional class IV symptoms (64% versus late 22%; p < 0.0001), unstable angina (87% versus late 65%; p < 0.0001), or a recent preoperative myocardial infarction (17% versus late 2%; p < 0.0001).

CONCLUSIONS

Carefully selected patients with significant left main stenosis can safely wait for operation with a low risk of complications. Early surgical intervention is allocated to patients with severe symptoms or recent preoperative myocardial infarction.

Left main coronary artery disease: assessment, diagnosis, and therapy

This article reviews and updates the current literature concerning the assessment, diagnosis, and therapy of coronary disease involving the LMCA. Included is recent information regarding the natural history, congenital abnormalities, noninvasive diagnostic studies, and role of coronary bypass surgery and percutaneous coronary interventions in treating disease of the LMCA. At present, it remains that the LMCA is a difficult segment to assess angiographically. The use of noninvasive imaging does not specifically distinguish LMCA from other types of coronary disease. Coronary bypass surgery has a proven benefit in the treatment of disease of the LMCA. Currently, interventional procedures are limited by significant risks, and surgical treatment with coronary bypass surgery remains the therapy of choice.

Dipyridamole stress echocardiography in patients with severe left main coronary artery narrowing. Echo Persantine International Cooperative (EPIC) Study Group--Subproject "Left Main Detection"

From a population of 2,698 patients (579 evaluated early after an uncomplicated acute myocardial infarction) who underwent dipyridamole echocardiography testing (DET) and subsequent coronary angiography, left main (LM) stenosis > or = 50% was present in 73 (61 men and 12 women, mean age 62 +/- 8 years). These 73 patients were compared with a control group comprising 100 consecutive coronary patients without LM disease. Both groups were similar regarding mean age, sex, incidence of previous myocardial infarction, left ventricular function at rest, and severity of coronary artery disease by the number of diseased vessels excluding the LM. The proportion of patients receiving antianginal therapy during DET was higher in the LM than in the non-LM group (32 vs 14%; p < 0.01). No major complication (severe hypotension, sustained arrhythmia, myocardial infarction or death) occurred during DET. Of 73 patients with LM disease, 68 had positive DET (sensitivity 93%), dipyridamole time was 7.1 +/- 3.8 minutes, and the rest-peak stress variation in dipyridamole wall motion score index (1 = normal to 4 = dyskinesia, in an 11-segment model) was 0.37 +/- 0.23; 14 patients (19%) were resistant to aminophylline and needed nitrates to resolve ischemia. In the non-LM group, DET was positive in 72% (p < 0.001 vs LM), with a longer dipyridamole time (9.6 +/- 5.2 minutes; p < 0.001 vs LM), lower rest-peak stress wall motion score index variation (0.29 +/- 0.25; p < 0.05 vs LM), and less frequent antidote resistance (1%; p < 0.001 vs LM).(ABSTRACT TRUNCATED AT 250 WORDS)

Left main coronary flow velocity associated with stenosis. Evaluation by transesophageal color-guided pulsed Doppler technique

To quantitatively estimate the extent of left main coronary artery (LMCA) stenosis, flow velocity of the LMCA in 33 patients was analyzed by a transesophageal color-guided pulsed Doppler technique. In 11 of 20 patients with LMCA stenosis, coronary flow velocity could be measured. The peak diastolic flow velocity at the stenotic segments was 90 +/- 32 (SD) cm/s which was significantly greater than that at the nonstenotic segments (n = 13; 34 +/- 8 cm/s; p < 0.01), and was correlated with the angiographically determined percentage of diameter stenosis of the vessel which ranged from 52 to 90 percent (r = 0.77; y = 6.34 square root of x + 10.4; p < 0.01). These results suggest that acceleration of flow velocity at the point of stenosis may be correlated with the severity of the stenosis. Measurement of flow at the point of stenosis by transesophageal color-guided pulsed Doppler technique may facilitate the quantitative assessment of LMCA stenosis, although its sensitivity requires improvement.

Bilateral internal mammary artery grafts in patients with left main coronary artery disease

The use of the internal mammary artery (IMA) in myocardial revascularization has been expanded with bilateral and sequential grafting. However, its application in the presence of left main coronary artery stenosis (LMCAS) has not been well established. From September 1983 through December 1990, 280 patients with LMCAS greater than 50% were revascularized (3.4 mean grafts per patient) with bilateral IMA and saphenous vein grafts. Eighty-one were sequential IMA grafts. There were 234 males (83.6%) and 46 females (16.4%) with a mean age of 64.4 years (range 39 to 84 years). Preoperatively, there were six patients (2.1%) in New York Heart Association (NYHA) Class I, 30 patients (10.7%) in Class II, 130 patients (46.4%) in Class III, and 114 patients (40.7%) in Class IV. Fifty-six patients (20.0%) had an ejection fraction less than 50%. Intraaortic balloon counterpulsation was used preoperatively in 26 patients (9.3%) and intraoperatively in 11 patients (3.9%). There were four hospital deaths (1.4%). Hospital complications included: reoperation for bleeding, 7 patients (2.5%); pulmonary insufficiency, 21 patients (7.5%); perioperative infarction, 14 patients (5.0%); and stroke, 4 patients (1.4%). Follow-up was obtained in 276 hospital survivors (100.0%) with a mean of 33.4 months. There were 20 late deaths (7.1%): seven cardiac related and 12 noncardiac related. Postoperative assessment reveals substantial functional improvement. These results furnish evidence that bilateral IMA grafts can be accomplished with a low operative risk and can provide excellent functional results in patients with LMCAS.

Predictors of early mortality in patients with angiographically documented left main coronary artery disease

To determine predictors of early death after coronary angiography in patients with significant left main coronary artery disease (greater than or equal to 60% diameter narrowing, LMCAD), we reviewed the clinical records of patients with LMCAD who died after angiography. Of 1,288 patients with LMCAD studied between January 1978 and October 1989, 21 died within 2 days after angiography (group 1). As a control group, 85 patients were randomly sampled from 1,196 patients who survived at least 30 days after angiography (group 2). The predictors of early death after angiography in patients with LMCAD were older age (P less than 0.05), New York Heart Association Class III or IV (P less than 0.005), shorter duration of unstable angina (P less than 0.005), higher left ventricular end-diastolic pressure (P less than 0.006), lower ejection fraction (P less than 0.005), and significant left circumflex artery disease (P less than 0.006). The use of heparin infusion after angiography did not appear to be a significant factor. It is suggested that earlier operation or more aggressive management be undertaken in patients who, at cardiac catheterization, have significant LMCAD associated with the above-listed variables.

Noninvasive identification of significant narrowing of the left main coronary artery by dipyridamole thallium scintigraphy

To evaluate the usefulness of dipyridamole thallium scintigraphy with low-level exercise for the identification of left main (LM) coronary artery disease (CAD), 466 consecutive patients with CAD were studied. Thirty-eight patients (8%) had LM stenosis (diameter narrowing greater than or equal to 50%). The LM scintigraphic pattern was present in 9 of 38 patients with LMCAD and 38 of 428 CAD patients without LMCAD (24 vs 9%; p less than 0.005). This pattern was present in 6 of 9 patients with LMCAD without right CAD and in only 3 of 29 patients with LM and right CAD (67 vs 10%; p = 0.0005). Patients with LMCAD had a higher incidence of premature cessation of low-level exercise (53 vs 21%; p less than 0.0001), chest pain (68 vs 48%; p less than 0.02), blood pressure decrease of greater than or equal to 20 mm Hg (44 vs 16%; p less than 0.002) and greater ST depression (0.17 +/- 0.13 vs 0.06 +/- 0.10 mV; p less than 0.001) during dipyridamole loading than patients without LMCAD. Stepwise discriminant analysis revealed that the LM scintigraphic pattern and markers of ischemia during dipyridamole loading best identified (p less than 0.0001) patients with LMCAD without right CAD (sensitivity 67%, specificity 91%), but this predictability is no better than the LM scintigraphic pattern alone. The combination of clinical markers of ischemia during dipyridamole loading and scintigraphic findings of diffuse slow washout, extensive fixed defects and the LM pattern best identified (p less than 0.0001) patients with LM and right CAD (sensitivity 72%, specificity 80%).(ABSTRACT TRUNCATED AT 250 WORDS)

Frequency and significance of complete atrioventricular block after coronary artery bypass grafting

Three hundred forty-eight consecutive patients were evaluated during 1985 and 1986 for the development of complete atrioventricular (AV) block after coronary artery bypass grafting. Cold (4 degrees) asanguineous potassium cardioplegia with temperature monitoring was used uniformly. AV block developed in 56 instances (16%). In 32 patients (group 1) the block was transient (less than 6 hours) and in 24 it was persistent (group 2). Left main coronary artery stenosis in conjunction with total obstruction of a dominant right coronary artery occurred more commonly in patients manifesting AV block (18 of 56, 32%) than in those without it (35 of 292, 12%) (p less than 0.05). Complete occlusion of a dominant right coronary artery was observed with equal frequency in patients with and without AV block. The presence of an ungraftable right coronary artery, however, was significantly more frequent in the AV block group: 16 of 37 (47%) vs 6 of 194 (3%) (p less than 0.01). Endarterectomy of the right coronary artery was performed in 8 of 24 patients (33%) with persistent AV block versus none in the patients with transient AV block (n = 32) or normal sinus rhythm postoperatively (n = 292) (p less than 0.0001). Persistent AV block (greater than 6 hours) was associated with myocardial infarction in 6 patients (25%) (p less than 0.05) and with low cardiac output in 18 patients (75%) (p less than 0.0001). In conclusion, AV block after myocardial revascularization was frequently associated with the presence of multivessel coronary disease and an ungraftable dominant right coronary artery. Persistent (greater than 6 hours) AV block was correlated with both perioperative myocardial infarction and low cardiac output.

Left main coronary artery disease: radionuclide angiographic function versus anatomic correlates with visual and quantitative angiographic methods

The results of exercise radionuclide angiography in 29 patients with significant left main coronary artery stenosis were examined to correlate functional left ventricular performance with anatomic severity of left main coronary artery stenosis. Change in ejection fraction, regional wall motion, and peak ejection fraction were widely variable; none of these parameters correlated with severity of left main stenosis as assessed by visual or quantitative angiographic methods. Twenty-five patients (86%) had two or more of the following indicators of ischemia with exercise: chest pain, significant ST-segment depression, systolic hypotension, definite decrease in ejection fraction, or definite decline in regional wall motion. However, four patients (14%) had only mild abnormalities in ejection fraction and regional wall motion, although they did have hemodynamic and electrocardiographic evidence of severe ischemia. Exercise radionuclide angiography yields heterogeneous results in patients with significant left main coronary artery stenosis. Anatomically severe left main coronary artery stenosis is not always associated with mechanical evidence of severe ischemia.

Surgical revascularization of left main coronary artery stenosis: determinants of perioperative and long-term outcome in the 1980s

The postoperative courses of 176 patients who underwent coronary artery bypass surgery for significant left main coronary artery stenosis were analyzed to determine which preoperative clinical and angiographic factors correlated best with outcome. Clinical variables included age, sex, New York Heart Association (NYHA) anginal class, presence of unstable angina, and surgical class. The angiographic variables included percentage of left main stenosis, presence of right coronary artery stenosis, coronary dominance, number of vessels diseased, myocardial jeopardy score, and ejection fraction. The overall perioperative mortality rate was 9.1%. There was a significant increase in perioperative mortality among female patients (p less than 0.05) and patients undergoing emergency surgery (p less than 0.05). Patients with left main stenosis of 80% or more or with balanced or left dominant circulation showed trends toward increased perioperative mortality. Life-table analysis showed that emergency surgery and left main stenosis of 80% or more correlated with increased long-term mortality (p less than 0.05). No other variable tested showed a significant correlation with either perioperative or long-term mortality. A comparison of these results with studies performed in the 1970s shows that there has been considerable change in those factors which place a patient at increased risk for mortality during surgical treatment of left main coronary artery stenosis.

Coronary artery bypass surgery in women

Coronary bypass surgery is performed more frequently in men than in women. A selection bias in favor of men may exist in currently utilized evaluation precesses for patients with both chest pain syndromes and documented coronary artery disease. Surgery should be considered in women with significant left main coronary artery stenosis, "left main equivalent" coronary disease, severe three-vessel coronary disease with/without left ventricular dysfunction, two-vessel coronary disease (including a proximal left anterior descending artery stenosis), and unstable angina pectoris with decreased left ventricular function. Women and men undergoing coronary bypass surgery seem to benefit from internal mammary artery grafts used alone or in combination with saphenous vein grafts. Surgical mortality, incomplete revascularization, early and late graft occlusion, and recurrent angina are more prevalent in women who undergo surgery. However, long-term mortality following surgery is similar in men and women.

Psychosomatic aspects of coronary artery bypass graft surgery. A prospective study of 101 male patients

101 consecutive male patients were examined by means of clinical interviews and depression, anxiety, personality, psychometric and life stress tests. The examinations took place preoperatively, on the 9th postoperative day (average) and 7.5 months after surgery. The mean age of the patients was 52.2 years and the mean duration of CHD was 6.7 years. Prior to surgery 77% had experienced myocardial infarction and 85% belonged to NYHA class III or IV. 74% had a 3-vessel disease. When the NYHA classification was used as criterion for rehabilitation the result was excellent. Postoperatively 80% belonged to NYHA class I or II. Hospital mortality rate was 4% and one patient died from myocardial infarction prior to the final follow-up. Preoperatively 17% of the study group were working. 87% of the patients experienced negative effects on work life, caused by CHD. Postoperatively 33% worked regularly. The postoperative work situation correlated with the duration of preoperative unemployment (p less than 0.0001), the patient's own opinion about work return (willingness/unwillingness to return to work) (p less than 0.01), as well as with the amount of negative life stress experienced preoperatively (p less than 0.01). Only 13% of the series experienced positive effects on work life, caused by CABG surgery. The majority of the patients had experienced negative effects on social and economic life (51%), as well as on sexual life (70%), caused by CHD. After surgery improvements were noted by 36% on social life and by 27% on sexual life. 15% experienced impairment of sexual life postoperatively. According to the Beck Depression Inventory 29% showed depression preoperatively, and 10% postoperatively. The difference is significant (p less than 0.0001). Clinically the figures tended to be higher. The same tendency holds for anxiety scores as measured by the Hamilton anxiety scale. The incidence of postoperative psychoses was 35%. Higher age (p less than 0.01) and/or absence of psychosomatic diseases (p less than 0.05) correlated with higher frequency of psychoses. Even though cardiological rehabilitation according to the NYHA classification was excellent, 22% of the series did not think their expectations were fulfilled. Psychic and social rehabilitation was in several aspects unsatisfactory, and the patients did not seem prepared for this. The importance to consider rehabilitation from a psychosomatic standpoint is clearly shown. To predict the result of rehabilitation preoperatively is not possible.

[Stenosis of the main trunk of the left coronary artery. Apropos of 54 cases]

In the 54 patients studied coronary arteriography alone showed stenosis of the left main coronary artery (a lesion observed in 5.2 p. 100 of pathological coronary arteriographies), associated with other coronary lesions, 72.2 p. 100 of which involved all three major vessels. Ventriculography was abnormal in 53 p. 100 of the cases, with a less than 45 p. 100 left ventricular ejection fraction in 37.4 p. 100 of them. Nine patients were considered inoperable; 4 of these died during a 40-month follow-up period under medical treatment. Forty-five patients underwent coronary bypass; there were 4 peri-operative deaths (8.9 p. 100), 8 post-operative myocardial infarctions (17.8 p. 100) and one late death (2.2 p. 100). These patients were followed up for a mean period of 26.4 months. All authors who have studied the subject agree that surgery is beneficial: not only does it improve cardiac function, but it also prolongs survival. In spite of the peri-operative risks, surgery must be contemplated in patients with a more than 50 p. 100 stenosis of the left main coronary artery, provided the cardiac vascular bed is accessible to revascularization.