Optical coherence tomography characterization of spontaneous recanalized coronary thrombus - Single center experience

Recanalized thrombus is an under diagnosed clinical entity. Aim was to investigate the utility of optical coherence tomography (OCT) in identifying spontaneously recanalized thrombi (SRCT) for management in clinical practice. This was a retrospective study analyzing 2678 coronary angiograms over a 4-year period which included intravascular imaging guidance in 75.8% of the percutaneous coronary interventions (PCI). Angiographic suspicion of SRCT has hazy appearance seen in 34 patients. Eight patients (7 males and 1 female) were confirmed with SRCT on OCT and two underwent intravascular ultrasound (IVUS). Median age was 52 years (range 33-67 years). Based on clinical symptoms, diagnosis was STEMI-2, NSTEMI-1, unstable angina-3 and chronic stable angina-2. Angiographic patterns were veiled/hazy appearances in 3; braided in 2; pseudo dissection in 2; and near occlusion in 1 patient. OCT findings displayed multiple small cavities, signal-rich with high backscattering and thin septa with smooth inner borders dividing the lumen and intercommunications. Presence of multiple holes conferred typical "Swiss cheese" or 'lotus root' like appearance, characteristic of recanalized thrombi. SRCT lesion length was (median interquartile ranges [IQR], 16.5[12.07-21.5] mm) and minimal luminal area (median [IQR], 1.77 [0.93-3.26] mm²) with significant stenosis (median [IQR], 74.0[67.0-81.0] %). Minimum/maximum number of channels were (median [IQR], 2.0[2.0-2.0]) and (median [IQR], 4.50[4.0-6.75]) respectively. Lipid rich plaque was predominant. IVUS demonstrated echo-lucent channels with small cavities. All but one patient underwent PCI. Intravascular imaging by OCT delineates the characteristics of recanalized thrombi and distinguishes ambiguous lesions. Majority of the lesions involving SRCT were significant both symptomatic and stenosis severity wise on OCT requiring PCI.