Identification of Coronary Artery Side Branch Supplying Myocardial Mass That May Benefit From Revascularization

JACC Cardiovasc Interv. 2017 Mar 27;10(6):571-581. doi: 10.1016/j.jcin.2016.11.033. Epub 2017 Mar 1.

Abstract

Objectives: The authors sought to identify whether a coronary side branch (SB) is supplying a myocardial mass that may benefit from revascularization.

Background: The amount of subtending myocardium and physiological stenosis is frequently different between the main vessel (MV) and SB.

Methods: In this multicenter registry, 482 patients who underwent coronary computed tomography angiography and fractional flow reserve (FFR) measurement were enrolled. The % fractional myocardial mass (FMM), the ratio of vessel-specific myocardial mass to whole myocardium, was assessed in 5,860 MV or SB consisting of 2,930 bifurcations. Physiological stenosis was defined by fractional flow reserve (FFR) <0.80. Myocardial mass that may benefit from revascularization was defined by %FMM ≥10%.

Results: In per-bifurcation analysis, MV supplied a 1.5- to 9-fold larger myocardial mass compared with SB. Unlike left main bifurcation (n = 482), only 1 of every 5 non-left main SB (n = 2,448) supplied %FMM ≥10% (97% vs. 21%; p < 0.001). SB length ≥73 mm could estimate %FMM ≥10% (c-statistic = 0.85; p < 0.001). In 604 vessels interrogated by FFR, diameter stenosis was similar (p = NS), but %FMM ≥10%, FMM/minimal luminal diameter, and frequency of FFR <0.80 was higher in MV compared with SB (p < 0.001, all). Generalized estimating equations modeling demonstrate that vessel diameter, left myocardial mass, and FFR were not (p = NS), but SB length ≥73 mm and left main bifurcation were significant predictors for %FMM ≥10% (p < 0.001).

Conclusions: Compared with MV, SB supplies a smaller myocardial mass and showed less physiological severity despite similar stenosis severity. SB supplying a myocardial mass of %FMM≥10%, which may benefit revascularization could be identified by vessel length ≥73 mm. Pre-procedural recognition of these findings may guide optimal revascularization strategy for bifurcation.

Keywords: bifurcation; fractional myocardial mass; side branch ischemia.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Area Under Curve
  • Computed Tomography Angiography*
  • Coronary Angiography / methods*
  • Coronary Artery Disease / diagnostic imaging*
  • Coronary Artery Disease / physiopathology
  • Coronary Artery Disease / therapy*
  • Coronary Stenosis / diagnostic imaging*
  • Coronary Stenosis / physiopathology
  • Coronary Stenosis / therapy*
  • Coronary Vessels / diagnostic imaging*
  • Coronary Vessels / physiopathology
  • Female
  • Fractional Flow Reserve, Myocardial*
  • Humans
  • Male
  • Middle Aged
  • Multidetector Computed Tomography*
  • Myocardial Revascularization*
  • Predictive Value of Tests
  • ROC Curve
  • Registries
  • Republic of Korea
  • Severity of Illness Index