Residual stress ischaemia is associated with blood markers of myocardial structural remodelling.

Background: Long-term prognosis of coronary artery disease (CAD) patients is worsened when stress ischemia persists on treatment, but the relationship with adverse cardiac remodelling had never been investigated. Aim: To analyze changes in blood markers of fibrosis in patients with chronic CAD exhibiting exercise ischaemia. Methods: Circulating markers of collagen: (i) turnover (amino-terminal propeptide of collagen-III [PIIINP]) and (ii) degradation (matrix metalloproteinase 1 [MMP-1]), were obtained in 139 CAD patients referred for exercise 201Tl-SPECT. Results: In the 57 patients who had SPECT-ischaemia, PIIINP was higher (4.3±2.9 μg L−1 vs. 3.1±1.5 μg L−1, p=0.002) and MMP-1 lower (3.8±2.1 μg L−1 vs. 4.7±2.8 μg L−1, p=0.04) than in the 82 patients without SPECT-ischaemia. PIIINP was independently related to LV volume, SPECT-ischaemia and age, whereas MMP-1 was related to current treatment with ACEI and β-blockers (p<0.05). In the 104 patients with a normal LV ejection fraction, only PIIINP was related to SPECT-ischaemia (4.1±2.2 μg L−1 vs. 3.1±1.5 μg L−1, p=0.01). Conclusion: In patients with chronic CAD, exercise ischaemia is associated with increased collagen-III turnover, independently of concomitant medications and even when LV ejection fraction is normal. Long-term, this increase might relate to adverse cardiac remodelling even when cardiac function is not clearly affected at baseline.