Morphological Plaque Characteristics and Clinical Outcomes in Patients With Acute Coronary Syndrome and a Cancer History.

Background Although patients with a cancer history have a 2 to 3 times higher risk for acute coronary syndrome (ACS), the morphological characteristics of ACS culprit plaque in those patients and their relations with clinical outcomes remain unknown. Methods and Results This retrospective, multicenter, observational cohort study included consecutive patients with ACS who underwent optical coherence tomography-guided emergent percutaneous coronary intervention. Patients were categorized into those without a cancer history, those with a cancer history, and those currently receiving cancer treatment. ACS culprit lesions were classified as plaque rupture, plaque erosion, or calcified nodule using optical coherence tomography. Plaque erosion frequency was significantly higher in culprit lesions of patients with current cancer and patients with cancer history than in those of patients without cancer history (56.3% versus 61.7% versus 36.5%). Calcified nodule incidence was significantly higher in patients without cancer history than in patients with current cancer and patients without cancer history (patients with current cancer: 12.4% versus patients without cancer history: 25.5% versus patients without cancer history: 12.6%, P<0.001). Cancer history was independently associated with nonplaque rupture (plaque erosion or calcified nodule) in ACS culprit lesions (odds ratio, 4.00; P<0.001). Cancer history was independently associated with major adverse cardiovascular events (hazard ratio [HR], 1.98; P=0.002). Nonplaque rupture in ACS culprit lesions was independently associated with major adverse cardiovascular events (HR, 1.60; P=0.011). Conclusions Patients with a cancer history had significantly worse clinical outcomes after ACS than those without a cancer history. Those with a cancer history had significantly higher plaque erosion and calcified nodule incidences in the ACS culprit lesions, which might partly explain their worse clinical outcomes. Registration URL: www.umin.ac.jp/ctr/index.htm. Unique Identifier: UMIN000038442.

Prediction of the debulking effect of rotational atherectomy using optical frequency domain imaging.

Whether predicting the rotational atherectomy (RA) effect based on the position of optical frequency domain imaging (OFDI) is accurate remains uncertain. The aim of this study was to evaluate the predictive accuracy of OFDI in identifying RA location and area. Twenty-five patients who underwent RA with OFDI were included. On pre-RA OFDI images, a circle with the dimension of a Rota burr was drawn at the center of the OFDI catheter. The area where the circle overlapped with the vessel wall was defined as the predicted ablation area (P-area), and the actual ablated area (A-area) was measured. The predictive accuracy of OFDI was evaluated as follows: overlapped ablation area (O-area: overlapping P- and A-areas) divided by P-area = %Correct-area, and A-area - O-area divided by A-area = %Error-area. Cross-sections were separated into four categories based on the median values of %Correct- and %Error-area. Among 334 cross-sections, RA effects were confirmed in the predicted location in 87% of them. The median %Correct- and %Error-areas were 43.1% and 64.2%, respectively. Floppy wire, narrow lumen area, OFDI catheter close to the intima, and large arc of calcium were independently associated with good prediction (high %Correct-/low %Error-areas). Non-left anterior descending lesions, OFDI catheter far from the wire, and OFDI catheter and wire far from the intima were associated with irrelevant ablation (low %Correct-/ high %Error-areas). The accuracy of the OFDI-based predictions for RA effects was acceptable with regard to location, but not high with regard to area. Wire types, target vessels, and OFDI catheter and wire positions are important determinants for accurately predicting RA effect using pre-procedural OFDI.

Techniques for reducing air bubble intrusion into the left atrium during radiofrequency catheter and cryoballoon ablation procedures: An ex vivo study with a high-resolution camera.

BACKGROUND: Air embolisms are serious complications during catheter ablation procedures. OBJECTIVES: The aims of the present study were to determine when air bubbles enter the left atrium (LA) during catheter ablation procedures and to identify techniques that reduce air bubble intrusion. METHODS: An ex vivo study was performed to monitor air bubbles using a silicone heart model and a high-resolution camera. In total, 280 radiofrequency catheter and cryoballoon ablation processes were tested. RESULTS: Small and large air bubbles were often observed during catheter ablation processes. Many small air bubbles arose during sheath flushing at fast speeds (15 mL/2 s) (median bubble number [quartiles]: 35 [20-53] for SL0, 35 [23-44] for Agilis, and 98 [91-100] for FlexCath) and during initial cryoballoon inflation/freezing/deflation (34 [22-47]). Large (≥1.5 mm) air bubbles were observed during Lasso catheter insertion (1 [0-1]), cryoballoon insertion (2 [1-2]), and initial inflation/freezing/deflation (1 [1-3]). Massive air bubbles were observed during Optima catheter insertion into the sheath using an inserter (10 [2-15]). Sheath flushing at slow speeds (15 mL/5 s) significantly reduced the number of air bubbles. Before cryoballoon insertion, temporary balloon inflation and air bubble removal from the inflated surface were most effective in reducing air bubble intrusions. Optima catheter insertion without an inserter significantly reduced large air bubble intrusion. CONCLUSION: Air bubbles entered the LA at specific times. Techniques such as sheath flushing at slow speeds, temporary cryoballoon inflation before insertion, inserting the Optima catheter without an inserter, and avoidance of negative pressure in the LA could reduce air bubble intrusion.

The importance of catheter stability evaluated by Visitag(TM) during pulmonary vein isolation.

BACKGROUND: The recurrence rates of atrial fibrillation (Af) after ablation are still high, and repeat procedures are required in these patients. The main reason for Af recurrence is the recovery of the conduction between the pulmonary veins and left atrium. The importance of catheter stability during the pulmonary vein isolation (PVI) is not well studied. PURPOSE: The purpose of this study was to evaluate the contact force (CF), stable ablation time, and power during conduction blocking lesion formation for PVI. METHODS: Thirty-two consecutive drug-refractory Af patients who underwent an initial PVI using CARTO 3 and Visitag were included. The CF, ablation time, force time integral (FTI), and ablation power were recorded by Visitag. Residual conduction gap points requiring touch-up ablation after an encircling linear ablation (R point), spontaneous reconnection points (S point), and dormant conduction points (D point) were considered as non-conduction blocking lesion points. Each ablation parameter for the non-conduction blocking lesion points was compared with the other lesion points. RESULTS: Twenty-one points in 16 patients were considered non-conduction blocking lesions. Ten were R, eight were S, and three were D points. The CF, ablation time, FTI, and power at the non-conduction blocking lesion points and other points were 12.0 g (7.0-21.5) and 12.0 g (9.0-16.0) (P = 0.9), 7.7 s (5.6-10.1) and 12.5 s (9.4-16.8) (P < 0.05), 103.0 g*s (62.0-174.5) and 149.0 g*s (104.0-213.0) (P < 0.05), and 30.0 W (22.5-30.0) and 30.0 W (30.0-30.0) (P = 0.06), respectively. CONCLUSIONS: Shorter ablation time recorded in Visitag lead to non-conduction blocking lesion.

Optical coherence tomography study of chronic-phase vessel healing after implantation of bare metal and paclitaxel-eluting self-expanding nitinol stents in the superficial femoral artery.

BACKGROUND: This study aimed to assess chronic-phase suppression of neointimal proliferation and arterial healing following paclitaxel-coated (PTX) and bare metal stent (BMS) implantation in the superficial femoral artery using optical coherence tomography (OCT). METHODS: Twenty-five patients with 68 stents underwent an 8-month OCT follow-up. Besides standard OCT variables, neointimal characterization and frequencies of peri-strut low-intensity area (PLIA), macrophage accumulation, and in-stent thrombi were evaluated. RESULTS: The mean neointimal thickness was significantly less with PTX stents (544.9±202.2 µm vs. 865.0±230.6 µm, p<0.0001). The covered and uncovered strut frequencies were significantly smaller and larger, respectively, in the PTX stent group vs. the BMS group (93.7% vs. 99.4%; p<0.0001, 4.0% vs. 0.4%; p<0.0001, respectively). Heterogeneous neointima was only observed in the PTX stent group (12.5% vs. 0%, p=0.017). The frequencies of PLIA and macrophage accumulation were significantly greater in the PTX stent group (87.2% vs. 67.6%, p=0.001 and 46% vs. 9.1%, p=0.003, respectively). CONCLUSION: After 8 months, reduced neointimal proliferation was observed with PTX stent implantation. On the other hand, delayed arterial healing was observed compared with BMS.