Effects of contrast medium viscosity into flushing port on artefacts during optical coherence tomography imaging.

BACKGROUND: Optical coherence tomography (OCT) is becoming the standard imaging modality for percutaneous coronary intervention (PCI) because of its high resolution. To perform appropriate OCT-guided PCI, it is necessary to avoid artefacts and obtain high-quality images. We investigated the relationship between artefacts and the viscosity of contrast media, which were used to remove air before OCT imaging catheter was inserted into guiding catheter. METHODS: We retrospectively analyzed every pullback of OCT examinations from January 2020 to September 2021. Cases were divided into two groups according to the type of contrast media used for catheter flushing: low-viscosity (Iopamidol-300, Bayer, Nordrhein-Westfalen, Germany) vs. high-viscosity (Iopamidol-370, Bayer). We evaluated the artefacts and quality of each OCT image and performed ex vivo experiments to compare differences in artefact frequencies using the two contrast media. RESULTS: A total of 140 pullbacks in the low-viscosity group and 73 pullbacks in the high-viscosity group were analyzed. The percentage of grade 2 and 3 images (with good quality) in the low-viscosity group was significantly lower (68.1 % vs. 94.5 %, p < 0.001). Rotational artefacts were significantly more common in the low-viscosity group (49.3 % vs. 8.2 %, p < 0.001). In multivariate analysis, using low-viscosity contrast media was a significant factor influencing the appearance of rotational artefacts and affecting image quality (odds ratio, 9.42; 95 % confidence interval, 3.58 to 24.8; p < 0.001). In ex vivo experiments, using low-viscosity contrast media was also a significant predictor of artefact occurrence during OCT (p < 0.01). CONCLUSIONS: The viscosity of the contrast agent used while flushing the OCT imaging catheter contributes to the appearance of OCT artefacts.

Endovascular Treatment of Subclavian Artery Occlusion by Surgical Exposure of the Proximal Brachial Artery at the Side of an Arteriovenous Fistula.

A 76-year-old man undergoing hemodialysis complained of pain and discoloration of his right finger. The hemodialysis arteriovenous fistula was in the right upper extremity. Ultrasonography showed right subclavian artery occlusion. The lesion could not be approached from the lower extremity and olecranon artery. Thus, we performed the procedure after exposing the proximal brachial artery. We were able to recanalize the subclavian artery and restore blood flow to the right upper extremity. When the lesion is on the side of the arteriovenous fistula and approaching from the lower extremity is difficult, exposure of the proximal brachial artery can be considered.

Malnutrition leads to the progression of coronary artery calcification in hemodialysis patients.

BACKGROUND: Malnutrition is considered a risk factor for cardiovascular disease in patients with chronic kidney disease. However, no in vivo studies have reported on using optical coherence tomography to evaluate the effect of nutritional status on coronary atherosclerosis in hemodialysis patients. We aimed to conduct a detailed analysis of the effect of nutritional status on the coronary arteries in hemodialysis patients. METHODS: Among 64 hemodialysis patients who underwent percutaneous coronary interventions, 41 that underwent optical coherence tomography imaging were included in this study. And, among them, 24 patients that could also be evaluated using OCT also at the 6-month follow-up were included in this study. The patients were divided into two groups based on nutritional evaluation using the geriatric nutritional risk index. Culprit and non-culprit lesions were evaluated at baseline and after 6 months. RESULTS: In the culprit lesions at baseline, the length of the lipid plaque was significantly smaller in the malnutrition group. In contrast, the thickness and length of the calcified plaque and the angle of the calcified nodule were significantly larger (each p < 0.01). In the non-culprit lesions, the 6-month change in the angle of the calcified plaque was significantly greater in the malnutrition group (p = 0.02). The significant factors that affected the change in the angle of calcification were "malnutrition at geriatric nutritional risk index" [odds ratio, 8.17; 95% confidence interval, 1.79 to 37.33; p < 0.01] and "serum phosphorus level" (odds ratio, 3.73; 95% confidence interval, 1.42 to 9.81; p < 0.01). CONCLUSIONS: Appropriate management of nutritional status is crucial for suppressing the progression of coronary artery disease in hemodialysis patients.

Efficacy of pressure gradient measurement using peripheral fractional flow reserve in common femoral artery: a case report.

Background: The severity of peripheral artery disease (PAD) is usually diagnosed by physiological assessments, such as the ankle brachial index (ABI) or peak systolic velocity (PSV) on ultrasonography. We examined peripheral fractional flow reserve (pFFR: distal mean pressure divided by proximal mean pressure) measured by a pressure wire and pressure gradient to diagnose PAD patients who do not have lowered ABI or high PSV on ultrasonography. Case summary: An 84-year-old woman with intermittent claudication in her left leg had severe calcification in the left common femoral artery (CFA) on angiography. The exercise-stress ABI of pre-endovascular therapy (EVT) was 1.05/0.98. In addition, the PSV of the left CFA on ultrasonography was 230 cm/s. However, the pFFR using papaverine and alprostadil in the left CFA was 0.86, which was a significant score. In addition, the systolic pressure gradient between the distal and proximal regions was >20 mmHg. We performed EVT for the lesion, and the pFFR improved to 0.96. The systolic pressure gradient was only 1 mmHg at the lesion. Discussion: Symptomatic PAD patients whose ABI or PSV on ultrasonography is insufficient for EVT could be diagnosed with ischaemia using a pressure gradient and pFFR.

Clinical Efficacy of Intracoronary Papaverine After Nicorandil Administration for Safe and Optimal Fractional Flow Reserve Measurement.

Fractional flow reserve (FFR) is considered the standard for assessment of the physiological significance of coronary artery stenosis. Intracoronary papaverine (PAP) is the most potent vasodilator used for the achievement of maximal hyperemia. However, its use can provoke ventricular tachycardia (VT) due to excessive QT prolongation. We evaluated the clinical efficacy and safety of the administration of PAP after nicorandil (NIC), a potassium channel opener that prevents VT, for optimal FFR measurement.A total of 127 patients with 178 stenoses were enrolled. The FFR values were measured using NIC (NIC-FFR) and PAP (PAP-FFR). We administered PAP following NIC (NIC-PAP). Changes in the FFR and electrogram parameters (baseline versus NIC versus PAP) were assessed and the incidence of arrhythmias after PAP was evaluated. In addition, we analyzed another 41 patients with 51 stenoses by assessing the FFR using PAP before NIC (PAP-NIC). After propensity score matching, the electrogram parameters between 2 groups were compared.The mean PAP-FFR was significantly lower than the mean NIC-FFR (0.82 ± 0.11 versus 0.81 ± 0.11, P < 0.05). The mean baseline-QTc, NIC-QTc, and PAP-QTc values were 425 ± 37 ms1/2, 424 ± 41 ms1/2, and 483 ± 54 ms1/2, respectively. VT occurred in only 1 patient (0.6%). Although PAP induced QTc prolongation (P < 0.05), the PAP-QTc duration was significantly shorter in NIC-PAP compared to PAP-NIC (P < 0.05).The administration of PAP with NIC may induce sufficient hyperemia and prevent fatal arrhythmia through reductions in the PAP-induced QTc prolongation during FFR measurement.

Right ventricular branch compromise after percutaneous coronary intervention and baseline chronic kidney disease: A high-risk combination associated with long-term prognoses in acute inferior myocardial infarction.

BACKGROUND: Right ventricular branch compromise (RVBC) following percutaneous coronary intervention (PCI) in patients with acute inferior myocardial infarction (AIMI) is associated with short-term adverse clinical outcomes. Chronic kidney disease (CKD) is also known to be a major risk factor after PCI in AIMI. However, little is known about the impact of RVBC and CKD on long-term prognosis. METHODS: From January 2009 to January 2019, we retrospectively enrolled 90 consecutive patients with ST-elevation AIMI who had a culprit lesion in the proximal-to-mid right coronary arteries and underwent PCI in our institution. After the measurement of the Thrombolysis in Myocardial Infarction frame counts in RV branches using post-PCI angiography, we divided them into two groups (RVBC, n = 49; non-RVBC, n = 41), and investigated their long-term prognosis for 43±31 months. The primary endpoint was the incidence of major adverse cardiac events (MACEs), including all-cause death, nonfatal MI, congestive heart failure requiring hospitalization, and life-threatening arrhythmia. RESULTS: Both groups showed similar clinical characteristics; however, the baseline right ventricular function after PCI was significantly worse in RVBC than in non- RVBC. Twenty-four MACEs occurred during the follow-up (RVBC vs. non-RVBC: 37% vs. 14%, p = 0.002). In the multivariate analysis, both RVBC and baseline CKD were powerful predictors of MACEs (RVBC: hazard ratio [HR] 2.85, CKD: HR 2.29). Baseline CKD showed higher hazard ratios of MACEs in RVBC (CKD: HR 7.19 vs. non-CKD: HR 0.24). CONCLUSIONS: The prognoses of RVBC after primary PCI in patients with AIMI were poor. Baseline CKD and RVBC were associated with poor long-term clinical outcomes.

Healed Erosion: The Role of Pre-interventional Optical Coherence Tomography in a Patient Clinically Suspected of Having Unstable Angina with Coronary Spasm.

A 46-year-old man complained of chest pain at rest for the past three months. His symptoms gradually exacerbated and were suspected of being due to unstable angina. A coronary angiogram revealed focal tight stenosis at the proximal left anterior descending coronary artery with gross spastic coronary findings. Optical coherence tomography (OCT) revealed layered low-intensity structures with microvessels and the accumulation of macrophages, which indicated progressive stenosis with multiple-layered organized thrombus caused by coronary erosion. We treated the stenosis using a drug-coated balloon instead of drug-eluting stents. There was no restenosis, and OCT revealed good plaque healing at follow-up. This case suggests that the pre-interventional OCT plaque morphology can have a positive impact on the revascularization strategy.

Comparison of post-stent irregular protrusion and subsequent neointimal characteristics between second- and third-generation drug-eluting stent implantation.

BACKGROUND: Third-generation drug-eluting-stents (3rd DES) may improve coronary arterial healing and reduce neoatherosclerosis formation. We evaluated post-stent findings and subsequent vascular healing of 3rd DES by comparing to second-generation drug-eluting-stents (2nd DES) at intermediate-term follow-up using optical coherence tomography (OCT). METHOD: We evaluated 170 patients with 170 lesions who underwent DES implantation (2nd DES, n = 98; 3rd DES, n = 72) and OCT-guided follow-up examination. After propensity score (PS) matching for baseline clinical characteristics, OCT findings from 56 pairs of patients with 2nd DES and 3rd DES implants were compared. Post-stent irregular protrusion (IP) was defined as the protrusion of material with an irregular surface into the lumen between the stent struts. Neoatheroscleosis was defined as neointima contained heterogeneous pattern, rupture, lipid-laden, thin-cap fibroatheroma, or calcification. The presence of peri-strut low-intensity area (PLIA) and in-stent neointimal tissue characteristics were also analyzed at 6- to 8-month follow-up. RESULTS: There were no significant differences between the incidence of post-stent IP or neoatherosclerosis formation in the 2nd DES and the 3rd DES (45% vs. 38%, p = 0.44; 30% vs. 20%, p = 0.19, respectively). However, the incidences of PLIA and layered neointimal pattern, which indicate immature neointimal healing, were significantly lower in the 3rd DES compared to the 2nd DES (41% vs. 61%, p = 0.04; 2% vs. 11%, p = 0.04, respectively). As comparing intermediate-term follow-up OCT neointimal findings in patients with IP between 2nd DES and 3rd DES, most neointima tended to have a homogeneous pattern (95% versus 76%, p = 0.06) in the 3rd DES than in the 2nd DES. CONCLUSIONS: The incidence of post-stent IP and subsequent neoatherosclerosis formation at intermediate-term follow-up after stent implantation were similar between patients with 2nd DES and 3rd DES, however, vascular healing might be favorable when using 3rd DES.

Acute myocardial infarction following sequential multi-vessel occlusion in a case of polycythemia vera.

A 59-year-old female was brought to our emergency room with severe chest pain. Based on the electrocardiogram (ECG) and echocardiography, an acute coronary syndrome (ACS) was suspected. Her initial ECG showed ST elevation in the inferior leads (II, III, and aVF), which had progressed to involve the anterior leads (V2-V4) by the time she was shifted to the catheterization room. A coronary angiogram revealed total occlusion of the mid-left anterior descending (LAD) artery and a filling defect of the distal right coronary artery. Although we had emergently treated her using thrombus aspiration following stent implantation, lots of thrombi re-formed on the stent. We surmised her ACS was primarily caused by thrombus formation due to polycythemia vera (PV) based on the presence of increased blood consistency on admission. We performed repetitive long-inflation using a perfusion balloon and repeated thrombus aspiration. Finally, she was diagnosed as an untreated case of PV as a result of detailed blood investigations. Thereafter, we successfully treated her using the combination of dual antiplatelet therapy and direct oral anticoagulant therapy. Our experience highlights the importance of an urgent identification of PV. Effective management strategies should be successfully implemented in such patients as soon as possible. .