Immediately after CTO PCI, basal microvascular resistance was reduced in the recanalized target vessel compared with an unobstructed reference vessel (MD -1.36 mm Hg/cm/s; P=0.008).
Observational (n=21)
How does microvascular resistance in a recanalized CTO vessel compare to an unobstructed reference vessel immediately after successful PCI?
Basal microvascular resistance is reduced in a recanalized CTO immediately after PCI compared to a reference vessel, while hyperemic microvascular resistance is preserved, and longer stented segments correlate with increased resistance.
Mean Difference: -1.36 (95% CI -2.33–-0.39)
Absolute Event Rate: 3.58% vs 4.94%
p-value: p=0.008
OBJECTIVES: The aim of this study was to compare microvascular resistance under both baseline and hyperemic conditions immediately after percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) with an unobstructed reference vessel in the same patient BACKGROUND: Microvascular dysfunction has been reported to be prevalent immediately after CTO PCI. However, previous studies have not made comparison with a reference vessel. Patients with a CTO may have global microvascular and/or endothelial dysfunction, making comparison with established normal values misleading. METHODS: After successful CTO PCI in 21 consecutive patients, coronary pressure and flow velocity were measured at baseline and hyperemia in distal segments of the CTO/target vessel and an unobstructed reference vessel. Hemodynamics including hyperemic microvascular resistance (HMR), basal microvascular resistance (BMR), and instantaneous minimal microvascular resistance at baseline and hyperemia were calculated and compared between reference and target/CTO vessels. RESULTS: After CTO PCI, BMR was reduced in the target/CTO vessel compared with the reference vessel: 3.58 mm Hg/cm/s vs 4.94 mm Hg/cm/s, difference -1.36 mm Hg/cm/s (-2.33 to -0.39, p = 0.008). We did not detect a difference in HMR: 1.82 mm Hg/cm/s vs 2.01 mm Hg/cm/s, difference -0.20 (-0.78 to 0.39, p = 0.49). Instantaneous minimal microvascular resistance correlated strongly with the length of stented segment at baseline (r = 0.63, p = 0.005) and hyperemia (r = 0.68, p = 0.002). CONCLUSIONS: BMR is reduced in a recanalized CTO in the immediate aftermath of PCI compared to an unobstructed reference vessel; however, HMR appears to be preserved. A longer stented segment is associated with increased microvascular resistance. © 2016 Wiley Periodicals, Inc.
Ladwiniec et al. (Tue,) conducted a observational in Chronic total coronary occlusion (n=21). Recanalized CTO vessel vs. Unobstructed reference vessel was evaluated on Basal microvascular resistance (BMR) (MD -1.36, 95% CI -2.33 to -0.39, p=0.008). Immediately after CTO PCI, basal microvascular resistance was reduced in the recanalized target vessel compared with an unobstructed reference vessel (MD -1.36 mm Hg/cm/s; P=0.008).
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