Impact of revascularization and myocardial viability determined by nitrate-enhanced Tc-99m sestamibi and Tl-201 imaging on mortality and functional outcome in ischemic cardiomyopathy

J Nucl Cardiol. Sep-Oct 2002;9(5):454-62. doi: 10.1067/mnc.2002.123913.

Abstract

Background: Nitrate-enhanced perfusion imaging has been shown to detect viability in dysfunctional myocardium, but nitrate-enhanced technetium 99m sestamibi has not been compared with nitrate-enhanced thallium 201.

Methods and results: Fifty-six patients with ischemic cardiomyopathy and heart failure (New York Heart Association classes II-IV) were scheduled for revascularization. Through use of a matching 12-segment model, nitrate-enhanced Tl-201 and Tc-99m sestamibi uptake at rest was assessed by 2 sets of blinded investigators. All single photon emission computed tomography data sets were read separately. Additional exercise Tc-99m sestamibi single photon emission computed tomography was performed on a separate day. Myocardial viability was thought to be present when the tracer uptake score was less than 3 (normal, 0; absent, 4). Of the 56 patients scheduled to undergo revascularization, only 23 (41%) underwent the procedure and the remainder continued medical therapy. Functional assessment by rest echocardiography was performed at 21 +/- 8 months, and survival was determined at 40 +/- 18 months. The baseline clinical and hemodynamic parameters were similar in the revascularization (n = 23) and medical therapy (n = 33) groups. Perfusion scores with nitrate-enhanced Tl-201 and Tc-99m sestamibi were similar in dysfunctional segments. Stress Tc-99m sestamibi reversible defects predicted significant improvement in left ventricular function compared with those without defects (P <.01) after revascularization. Cox regression model showed that when at least 5 reversible segments were viable, revascularization produced greater improvements in New York Heart Association class, a better trend toward survival (P =.07 for Tl-201 and P =.06 for Tc-99m), and a significantly greater impact on reverse remodeling.

Conclusions: Myocardial viability determined by nitrate-enhanced Tl-201 and myocardial viability determined by Tc-99m sestamibi are equivalent for predicting functional improvements, remodeling, and survival after revascularization in patients with ischemic cardiomyopathy.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Exercise Test
  • Female
  • Follow-Up Studies
  • Heart / diagnostic imaging
  • Heart / drug effects
  • Heart / physiopathology*
  • Heart Failure / diagnostic imaging
  • Heart Failure / etiology
  • Heart Failure / mortality
  • Heart Failure / surgery
  • Humans
  • Male
  • Myocardial Ischemia / complications
  • Myocardial Ischemia / diagnostic imaging*
  • Myocardial Ischemia / mortality*
  • Myocardial Ischemia / surgery
  • Myocardial Revascularization / mortality
  • Nitroglycerin* / pharmacology
  • Radiopharmaceuticals
  • Severity of Illness Index
  • Single-Blind Method
  • Survival Rate
  • Technetium Tc 99m Sestamibi*
  • Thallium*
  • Tomography, Emission-Computed, Single-Photon
  • Treatment Outcome

Substances

  • Radiopharmaceuticals
  • thallium chloride
  • Technetium Tc 99m Sestamibi
  • Thallium
  • Nitroglycerin