Functional recovery after percutaneous revascularization of coronary chronic total occlusions: insights from cardiac magnetic resonance tissue tracking

Abstract

To evaluate the effect of percutaneous coronary intervention (PCI) of coronary chronic total occlusions (CTOs) on left ventricular (LV) strain assessed using cardiac magnetic resonance (CMR) tissue tracking. In 150 patients with a CTO, longitudinal (LS), radial (RS) and circumferential shortening (CS) were determined using CMR tissue tracking before and 3 months after successful PCI. In patients with impaired LV strain at baseline, global LS (10.9 ± 2.4% vs 11.6 ± 2.8%; P = 0.006), CS (11.3 ± 2.9% vs 12.0 ± 3.5%; P = 0.002) and RS (15.8 ± 4.9% vs 17.4 ± 6.6%; P = 0.001) improved after revascularization of the CTO, albeit to a small, clinically irrelevant, extent. Strain improvement was inversely related to the extent of scar, even after correcting for baseline strain (B = − 0.05; P = 0.008 for GLS, B = − 0.06; P = 0.016 for GCS, B = − 0.13; P = 0.017 for GRS). In the vascular territory of the CTO, dysfunctional segments showed minor improvement in both CS (10.8 [6.9 to 13.3] % vs 11.9 [8.1 to 15.0] %; P < 0.001) and RS (14.2 [8.4 to 18.7] % vs 16.0 [9.9 to 21.8] %; P < 0.001) after PCI. Percutaneous revascularization of CTOs does not lead to a clinically relevant improvement of LV function, even in the subgroup of patients and segments most likely to benefit from revascularization (i.e. LV dysfunction at baseline and no or limited myocardial scar).

Territorial Post‐Revascularization Remodeling of Chronic Coronary Syndromes: Cardiac Magnetic Resonance Feature Tracking Study

“…Additionally, they reported significant improvement of GCS and of TCS of CTO territory in 150 patients. They also showed a significant 3‐month post PCI improvement of GRS by MRI‐FT in five CTO patients with impaired pre‐PCI GRS 19 . This is not in agreement with the current study, which may be due to different follow‐up duration, sample size and more selective inclusion criteria.…”

“…The significant improvement in LCX TLS, which was not shown in the current study, may be due to different post‐PCI follow‐up intervals and different population size 18 . A further study by Everaars et al showed that while there was no significant GLS improvement by MRI‐FT following PCI in 150 CTO patients, there was a significant improvement in GLS in the 51‐patient sub‐group with impaired pre‐PCI GLS 19 …”

“…They also showed a significant 3-month post PCI improvement of GRS by MRI-FT in five CTO patients with impaired pre-PCI GRS. 19 This is not in agreement with the current study, which may be due to different follow-up duration, sample size and more selective inclusion criteria. They also reported no significant improvement of TRS of CTO territory in 150 patients.…”

“…18 A further study by Everaars et al showed that while there was no significant GLS improvement by MRI-FT following PCI in 150 CTO patients, there was a significant improvement in GLS in the 51-patient sub-group with impaired pre-PCI GLS. 19 In the current study, there was a significant improvement in post-PCI GCS. In addition, pre-PCI and post-PCI TCS showed a significant improvement in the LAD, LCX and RCA coronary territories.…”

Does chance really favor (only) the prepared mind? The role of MRI tissue-tagging in solving a most vexing problem for the interventionalist

“…So in this month's Journal, we learned that another group of investigators have seemingly stumbled on their own Eureka moment, employing intramyocardial radio-frequency tissue tagging to investigate local cardiac strains following angioplasty in high-risk cases [12].…”