Thorac Cardiovasc Surg 2016; 64 - ePP49
DOI: 10.1055/s-0036-1571732

Transischemic Dilation as Predictor for Heart Failure in SPECT Data Analysis of Patients with Heart Disease

M. Keuchel 1, H. Höffken 2, N. Mirow 1, S. Vogt 1, R. Moosdorf 1
  • 1Department of Heart Surgery, Philipps-University, Marburg, Germany
  • 2Department of Nuclear Medicine, Philipps-University, Marburg, Germany

Objectives: Transient ischemic dilation ratio (TID) of the left ventricle is a significant predictor of future cardiac events in patients with otherwise normal myocardial perfusion SPECT. TID is a marker for subendocardial perfusion reduction after exercise in gated SPECT studies. Increased TID is correlated with concentric or excentric left-ventricular hypertrophy, or increased pre- or afterload conditions. This parameter is suggested to be an indicator for deterioration of subendocardial perfusion and offers a more precise presumptive screening for myocardial dysfunction.

Patients and Methods: Fifteen patients were involved in a non-gated SPECT rest and exercise study. After calculation of the endocardial volumes (bounded by the endocardial surface and the valve plane), computer-assisted evaluation (Corridor4DM SPECT, INVIA, Ann Arbor, United States) derives the transischemic dilatation (TID) ratio as the ratio of LV volumes at stress and rest (Vols = volume in stress, Volr = volume in rest). Further morphometric data were collected by subsequent CT scans: myocardial mass of the ventricles (MassStress, MassRest), end diastolic volume (EDVStress, EDVRest) in stress and rest, and ejection fraction (EF). The Mass/EDV ratios (M/E) were calculated.

Results: In the randomized group of patients with cardiovascular diseases the TID ranged from 0.82 to 1.24. The M/E ratio from rest to stress paralleled the increasing TID in an inverse manner (Fig. 1). In case of TID < 1.0 the M/E ratio increased whereas when TID > 1.0 the M/E ratio decreased (blue line). According to the formula for non-invasive volume-based wall stress index (σi)1 an increased myocardial wall stress accompanies a reduced TID.

Conclusion: Noninvasive parameter TID has promising value for description of deteriorations in myocardial blood malperfusions. Increased TID may be a good indicator for cardiac events. Decreased TID may indicate increased pathological wall stress during exercise.

Fig. 1 VVS vs. TID as predictor for heart disease.

Reference

References

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