iFR uncovers profound but mostly reversible ischemia in CTOs and helps to optimize PCI results

Abstract

Objectives The study aimed to demonstrate through instant wave‐free ratio (iFR) measurements that myocardium distal to a chronic total occlusion (CTO) is ischemic, that ischemia is reversible by PCI, and that iFR assessment after PCI can be used to optimize PCI results. Background The greatest benefit of revascularization is found in patients with low fractional flow reserve. In patients with CTOs, iFR measurement may be more appropriate to evaluate ischemia as it does not require maximal microvascular vasodilation, which may be hampered by microvascular dysfunction. Methods The iFR was measured in 81 CTO patients, both pre‐ and post‐PCI in 63 patients, and only post‐PCI in the following 18 patients. A pressure wire pullback was performed post‐PCI if iFR ≤0.89. Results The first 63 patients all had significant ischemia distal to the CTO with a median iFR of 0.33 [0.22; 0.44], improving significantly post‐PCI to a median iFR of 0.93 [0.89;0.96] (p < .001). In the complete cohort, the median iFR post‐PCI was 0.93 [0.86;0.96] but still ≤0.89 in 23 patients (30%). 12 of these patients had further PCI optimization because of a residual focal pressure gradient on pullback, after which only two had a final iFR ≤0.89. Conclusions In CTO patients with an indication for PCI, iFR consistently demonstrated profound myocardial ischemia. Successful PCI immediately relieved ischemia in 70% of patients. In the remaining 30% of cases, a manual iFR pullback proved helpful in guiding further optimization of the PCI result.

Percutaneous coronary intervention of chronic total occlusion - to whom, when and why

“…Pacienti s přítomným CTO a implantovaným kardiovertrem -defibrilátorem v primární či sekundár-ní prevenci náhlé srdeční smrti mají vyšší četnost adekvátních výbojů pro maligní arytmie ve srovnání s pacienty s ischemickou chorobou srdeční bez přítomného CTO (9). (11).…”

Is it time for a “functional” hybrid algorithm to optimize interventional results in chronic total occlusion?

“…Contrary to this assumption, the classic study by Werner et al 1 demonstrated in 62 patients, and later in a 50‐patient study by Sachdeva et al 2 that no matter how extensive were collaterals to a CTO, the myocardium was ischemic in many patients at rest and universally ischemic during stress. In the current issue of CCI, Kayaert et al 3 have extended these observations by using instantaneous wave‐free ratio (iFR) and demonstrated that myocardium subtended by a CTO is universally ischemic at rest by Pd/Pa [0.47 (0.37; 0.56)] and iFR [0.33 (0.22; 0.44)].…”

Subcutaneous cardioverter-defibrillator, patient selection, implantation, postoperative management in the Krasnoyarsk

“…Фракционный резерв кровотока и вариант этого метода -определение моментального резерва кровотока (мРК), не требующего введения вазодилатирующих препаратов, являются наиболее часто используемыми методами оценки значимости атеросклеротического поражения [5]. Однако в случае многососудистого поражения коронарного русла показатели данных тестов могут быть вариабельными [7,8]. Представленный клинический случай иллюстрирует динамику показателя мРК у пациентки с многососудистым поражением коронарного русла в результате этапного стентирования коронарных артерий.…”