Predictors of outcome of medically treated patients with left main/three-vessel coronary artery disease by coronary angiography

The Prognostic Importance of Nonsignificant Left Main Coronary Artery Disease in Patients Undergoing Percutaneous Coronary Intervention

OBJECTIVES

The purpose of this research was to study the association between nonsignificant (<50%) left main coronary artery disease (LMCAD) and short- and long-term survival in patients undergoing percutaneous coronary intervention (PCI).

BACKGROUND

The prognostic importance of nonsignificant LMCAD is unknown; however, the co-existence of nonsignificant LMCAD may influence revascularization decisions.

METHODS

We analyzed mortality and repeat catheterization rates of 11,855 patients in a prospective cardiac registry database who underwent single-vessel or multivessel PCI from January 1996 through December 2001. Of this cohort, 11.7% (n = 1,385) had nonsignificant (<50%) LMCAD. Outcomes were compared with those without LMCAD. A secondary analysis was performed on a larger cohort of 34,586 patients undergoing cardiac catheterization, irrespective of mode of revascularization therapy.

RESULTS

Patients with nonsignificant LMCAD had more co-morbidities, and a significantly higher crude mortality rate at 1 year compared with those without LMCAD (4.4% vs. 3.4%; p = 0.05). The 7-year crude mortality hazard ratio (HR) of PCI patients with <50% LMCAD versus those with no LMCAD was 1.18 (95% confidence interval [CI] 0.94 to 1.46). After risk adjustment for differences in baseline clinical profile, however, the HR decreased to 0.98 (95% CI 0.79 to 1.23). Repeat catheterization rates at 1 year did not differ between groups. The secondary analysis in all patients with nonsignificant LMCAD showed an adjusted HR of 1.03 (95% CI 0.94 to 1.14).

CONCLUSIONS

Patients undergoing single-vessel or multivessel PCI who have <50% LMCAD have a nonsignificantly increased 18% relative risk for mortality compared with those without detectable LMCAD that appears to be related to these patients' higher incidence of co-morbidities rather than the left main stenosis itself.

[Clinical predictors of the presence of perfusion defects in more than than one territory in myocardial scintigraphy with GATED-SPECT]

BACKGROUND AND OBJECTIVE

Extension of perfusion defects is associated with outcome in patients undergoing myocardial scintigraphy. The study aimed to identify the clinical characteristics that can predict the existence of perfusion defects in more than one territory in patients referred for myocardial scintigraphy with GATED-SPECT.

PATIENTS AND METHODS

A total of 193 patients undergoing myocardial scintigraphy with GATED-SPECT (99mTc-tetrofosmine) were studied. Clinical variables and scintigraphy results were studied to determine what clinical variables are associated with perfusion defects in more than one territory.

RESULTS

The number of territories with perfusion defects per patient was 1.1 0.8 and 29% had perfusion defects in > 1 territory. Patients with greater probability of having perfusion defects in > 1 territory were those with previous myocardial infarction (44% vs 21%, p = 0.030) and males (33% vs 10%, p = 0.006). In addition, patients with > 2 coronary risk factors had a statistical tendency to have defects in > 1 territory (47% vs 20%, p = 0.057). Only 15% of the patients with one of these three characteristics had perfusion defects in > 1 territory in comparison with 45% and 83% in those with 2 or 3 factors, respectively.

CONCLUSION

Considering 3 simple clinical characteristics (male gender, previous infarction and existence of > 2 coronary risk factors), it is possible to predict which patients are more likely to show perfusion defects in > 1 territory during GATED-SPECT myocardial scintigraphy.

Cardiac nuclear medicine in monitoring patients with coronary heart disease

Patient monitoring is a major indication for cardiac nuclear medicine procedures. Stress myocardial perfusion scintigraphy was initially used for diagnosis, but monitoring patients with coronary artery disease has become more common. Stress myocardial perfusion scintigraphy has been shown to provide a considerable amount of incremental prognostic information, which may be useful in selecting patients for therapy. In patients being considered for revascularization, fluorodeoxyglucose can be used to identify regions of dysfunctional but viable myocardium, even within regions that show fixed defects on stress perfusion imaging. It can be used to select a group of patients who will improve function with revascularization and who may have an improved outcome. Thus, cardiac nuclear medicine plays a pivotal role in monitoring patients with coronary artery disease.