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Transient left ventricular cavitary dilation during dipyridamole-thallium imaging as an indicator of severe coronary
J Lette1, J Lapointe, D Waters
1Maisonneuve Hospital, Montreal, Quebec, Canada.
Insights
Transient left ventricular cavitary dilation during dipyridamole-thallium imaging indicates severe coronary artery disease. This finding predicts a poor prognosis and increased risk of cardiac events, especially after noncardiac surgery.
Area of Science:
- Cardiology
- Nuclear Cardiology
- Diagnostic Imaging
Background:
- Dipyridamole-thallium imaging is a common diagnostic tool for assessing coronary artery disease.
- Transient left ventricular (LV) cavitary dilation is an observed phenomenon during this imaging technique.
- The clinical significance and prognostic implications of this dilation require further investigation.
Purpose of the Study:
- To determine the prevalence of transient LV cavitary dilation during dipyridamole-thallium imaging.
- To assess the association between transient LV cavitary dilation and the severity of coronary artery disease.
- To evaluate the prognostic value of transient LV cavitary dilation regarding cardiac events and postoperative complications.
Main Methods:
- Retrospective analysis of 510 consecutive patients undergoing dipyridamole-thallium imaging.
- Correlation of imaging findings with clinical data, hemodynamic parameters, and coronary angiography results.
- Follow-up assessment for cardiac events and analysis of postoperative cardiac event rates in patients undergoing noncardiac surgery.
Main Results:
- Transient LV cavitary dilation occurred in 9% of patients (45/510).
- Patients with dilation frequently had severe coronary artery disease (75% had left main, 3-vessel, or high-risk 2-vessel disease).
- Dilation was a strong predictor of poor prognosis, with a high rate of cardiac events (64%) in those not revascularized, and significantly increased postoperative cardiac event rates (58%) compared to other imaging findings.
Conclusions:
- Transient LV cavitary dilation during dipyridamole-thallium imaging is a significant marker of severe coronary artery disease.
- This finding portends a poor prognosis and identifies patients at high risk for future cardiac events.
- The presence of transient LV dilation predicts a substantially elevated risk of cardiac complications following noncardiac surgery.
Abstract:
Transient left ventricular (LV) cavitary dilation during dipyridamole-thallium imaging was reported in 45 of 510 (9%) consecutive patients referred for dipyridamole-thallium imaging. Clinical and hemodynamic effects observed during dipyridamole infusion were not predictive of transient cavitary dilation on the thallium images. Coronary angiography was performed in 32 of the 45 patients: 75% had either left main, 3-vessel or "high-risk" 2-vessel coronary artery disease. Although 25 of 45 patients (56%) with transient cavitary dilation were either asymptomatic or had only grade 1/4 effort angina, 16 of 25 patients (64%) not referred for coronary revascularization sustained a cardiac event during a mean follow-up of 12 months. Most events were cardiac deaths (75%) and 87% of events occurred within 4 months of the test. Noncardiac surgery was performed in 187 of the 510 patients. The postoperative cardiac event rate was 2% in the 101 patients with normal scans or fixed defects, 19% in 75 patients with reversible perfusion defects and 58% in 12 patients with reversible cavitary dilation (p less than 0.0001). Thus, transient LV dilation during dipyridamole-thallium imaging is a marker of severe underlying coronary artery disease, denotes a poor prognosis and predicts a high risk of postoperative cardiac complications in patients who undergo noncardiac surgery.