Effect of contact vector direction on achieving cavotricuspid isthmus block.

Cavotricuspid isthmus (CTI) ablation is an important treatment strategy for CTI-dependent atrial flutter (AFL). The location of the catheter contact area is confirmed by the contact vector direction (CVD) through three-dimensional mapping during the procedure. However, the relationship between CVD during radiofrequency ablation and its efficacy in achieving CTI block has not been clarified. This study aimed to investigate the relationship between CVD and efficacy in achieving CTI block. CVDs during radiofrequency ablation were divided into proximal vectors against the distal tip (P-vector) and other vectors (normal-vector). In 39 patients who underwent CTI linear ablation, the CTIs were divided into two segments: the tricuspid valve area (anterior) and inferior vena cava area (posterior). The frequency of the residual conduction gap was compared between segments in which the P- and normal-vectors were observed. P-vectors were observed in 13 of the 78 segments. The median ablation index was not significantly different between segments in which the P-vector and normal-vector were observed (398.2 [384.2-402.2] vs. 393.3 [378.3-400.1], p = 0.15). However, residual conduction gaps were significantly more frequently observed in the segment in which the P-vector was observed than those in which only the normal-vector was observed (6/13, 46.2% vs. 3/65, 4.6%; p < 0.01). During a 6-month follow-up, two patients required a second session of ablation due to AFL recurrence. A residual conduction gap was observed in one patient at the site where the P-vector was observed in the first session. Avoiding the P-vector might be an important factor in improving CTI block and reducing AFL recurrence.

Characteristics, Antithrombotic Patterns, and Prognostic Outcomes in Claudication and Critical Limb-Threatening Ischemia Undergoing Endovascular Therapy.

PURPOSE: The underlying difference between intermittent claudication (IC) and critical limb-threatening ischemia (CLTI) still remains unclear. This prospective multicenter observational study aimed to clarify differences in clinical features and prognostic outcomes between IC and CLTI, and prognostic factors in patients undergoing endovascular therapy (EVT). MATERIALS AND METHODS: A total of 692 patients with 808 limbs were enrolled from 20 institutions in Japan. The primary measurements were the 3-year rates of major adverse cardiovascular event (MACE) and reintervention. RESULTS: Among patients, 79.0% had IC and 21.0% had CLTI. Patients with CLTI were more frequently women and more likely to have impaired functional status, undernutrition, comorbidities, hypercoagulation, hyperinflammation, distal artery disease, short single antiplatelet and long anticoagulation therapies, and late cilostazol than patients with IC. Aortoiliac and femoropopliteal diseases were dominant in patients with IC and infrapopliteal disease was dominant in patients with CLTI. Patients with CLTI underwent less frequently aortoiliac intervention and more frequently infrapopliteal intervention than patients with IC. Longitudinal change of ankle-brachial index (ABI) exhibited different patterns between IC and CLTI (pinteraction=0.002), but ABI improved after EVT both in IC and in CLTI (p<0.001), which was sustained over time. Dorsal and plantar skin perfusion pressure in CLTI showed a similar improvement pattern (pinteraction=0.181). Distribution of Rutherford category improved both in IC and in CLTI (each p<0.001). Three-year MACE rates were 20.4% and 42.3% and 3-year reintervention rates were 22.1% and 46.8% for patients with IC and CLTI, respectively (log-rank p<0.001). Elevated D-dimer (p=0.001), age (p=0.043), impaired functional status (p=0.018), and end-stage renal disease (p=0.019) were independently associated with MACE. After considering competing risks of death and major amputation for reintervention, elevated erythrocyte sedimentation rate (p=0.003) and infrainguinal intervention (p=0.002) were independently associated with reintervention. Patients with CLTI merely showed borderline significance for MACE (adjusted hazard ratio 1.700, 95% confidence interval 0.950-3.042, p=0.074) and reintervention (adjusted hazard ratio 1.976, 95% confidence interval 0.999-3.909, p=0.05). CONCLUSIONS: The CLTI is characterized not only by more systemic comorbidities and distal disease but also by more inflammatory coagulation disorder compared with IC. Also, CLTI has approximately twice MACE and reintervention rates than IC, and the underlying inflammatory coagulation disorder per se is associated with these outcomes. CLINICAL IMPACT: The underlying difference between intermittent claudication (IC) and critical limb-threatening ischemia (CLTI) still remains unclear. This prospective multicenter observational study, JPASSION study found that CLTI was characterized not only by more systemic comorbidities and distal disease but also by more inflammatory coagulation disorder compared to IC. Also, CLTI had approximately twice major adverse cardiovascular event (MACE) and reintervention rates than IC. Intriguingly, the underlying inflammatory coagulation disorder per se was independently associated with MACE and reintervention. Further studies to clarify the role of anticoagulation and anti-inflammatory therapies will contribute to the development of post-interventional therapeutics in the context of peripheral artery disease.

Incidence, clinical characteristics, and diagnostic approach in transthyretin amyloid cardiomyopathy: The Kumamoto Cardiac Amyloidosis Survey.

BACKGROUND: In recent years, transthyretin amyloid cardiomyopathy (ATTR-CM) has received increasing attention; however, the epidemiology of ATTR-CM in Japan is not yet understood. In the Kumamoto Cardiac Amyloid Survey, we evaluated the current incidence, clinical characteristics, diagnostic approaches, and treatment strategies for ATTR-CM and compared tafamidis-prescription hospitals with regional hospitals. METHODS: We conducted a retrospective multicenter observational cohort study. The registry included patients with ATTR-CM diagnosed in two tafamidis-prescription hospital institutes [Japanese Circulation Society (JCS)-certified facilities] and 15 regional cardiovascular facilities in Kumamoto between January 2018 and December 2020. RESULTS: In total, 174 patients were diagnosed with ATTR-CM. The incidence of ATTR-CM was estimated to be approximately 1 per 10,000 person-years in the elderly population (>65 years old) in Kumamoto. Compared with that in the JCS-certified facilities cohort (n=115), age at diagnosis was significantly older (84.5 ± 5.6 vs. 77.5 ± 6.3 years old; p<0.01) in the regional hospitals cohort (n=59). Histological (25% vs. 81%; p<0.01) and genetic diagnosis (7% vs. 82%) were also less frequently performed. Probable (as indicated by positive bone scintigraphy findings with confirmation of monoclonal protein absence) and possible (as indicated by positive bone scintigraphy findings without confirmation of monoclonal protein absence) ATTR-CM accounted for the majority of cases (75% vs. 19%; p<0.01) in the regional hospitals cohort compared to the JCS-certified facilities cohort. There were no cases of hereditary ATTR-CM among the patients who underwent TTR genetic testing (n=98). CONCLUSIONS: We confirmed the incidence of ATTR-CM in Kumamoto and the diagnostic approach used in patients with ATTR-CM. Further prospective studies with a larger sample are needed to validate our results and to further shed light on the epidemiology of ATTR-CM in Japan.

Risk Factors and Prevalence of Deep Vein Thrombosis After the 2016 Kumamoto Earthquakes.

BACKGROUND: After previous earthquakes, a high prevalence of deep vein thrombosis (DVT) has been reported. We examined DVT prevalence and risk factors in evacuees of the Kumamoto earthquakes by performing mobile DVT screening at various evacuation centers around the epicenter. Methods and Results: For 1 month after the Kumamoto earthquake on 14 April 2016, mobile DVT screening using portable ultrasonography (US) was performed at 80 evacuation centers. Questionnaires, physical examination, and US of the lower limb were carried out, and simple D-dimer measurements were undertaken for DVT-positive examinees. The total number of examinees was 1,673, of whom 178 (10.6%) had DVT. The prevalence of DVT seemed to be gradually decreasing in the screening period, but age, use of sleep medication, prevalence of hypertension, dyslipidemia, leg edema, and lower leg varix were significantly higher in the DVT positive group than in the negative group. On multivariable logistic regression analysis, high age (≥70 years old), use of sleep medication, lower leg edema, and lower leg varix were significant predictors of DVT. In examinees with these 4 predictors, the DVT positive rate was 71.4%. CONCLUSIONS: In the first month after the Kumamoto earthquakes, DVT prevalence and severity, evaluated on D-dimer level, decreased with the passage of time. Mobile DVT screening indicated significant factors stratifying DVT risk in the evacuees.

Low contrast material dose coronary computed tomographic angiography using a dual-layer spectral detector system in patients at risk for contrast-induced nephropathy.

OBJECTIVE:: To evaluate the effects of virtual monochromatic imaging (VMI) using dual-layer spectral detector CT on the image quality of coronary CT angiography (CCTA) acquired by using a low contrast material (CM) dose. METHODS:: We used a VMI 50keV protocol with a 50% CM dose (140 mgI kg-1) to scan 30 patients with renal insufficiency and a 120 kVp with the standard CM dose (280 mgI kg-1) to scan 30 controls without renal insufficiency. Quantitative parameters, including CT attenuation, image noise, and contrast-to-noise ratio (CNR), were measured. The visual image quality factors of contrast enhancement, image noise, beam-hardening artefact, vessel sharpness, and overall image quality were scored on a 4-point scale. RESULTS:: The mean CT attenuation of the ascending aorta was significantly higher for 50 keV VMI than for 120 kVp. Image noise was significantly lower under the 50 keV VMI. CNR and the mean visual score for contrast enhancement were significantly higher for 50 keV VMI. There were no significant differences in the other visual image quality parameters between the two protocols. CONCLUSION:: Dual-layer spectral detector CT using 50 keV VMI enabled reducing the CM dose by 50 % without CCAT image quality degradation in patients with renal insufficiency. ADVANCES IN KNOWLEDGE:: The VMI 50 keV protocol using dual-layer spectral detector CT and a CM dose reduced by 50 % (140 mgI kg-1) can improve the diagnostic image quality of CCTA.

The Influence of Iterative Reconstruction on Coronary Artery Calcium Scoring-Phantom and Clinical Studies.

RATIONALE AND OBJECTIVES: We compared the effect of iterative model reconstruction (IMR), filtered back projection (FBP), and hybrid iterative reconstruction (HIR) on coronary artery calcium (CAC) scoring. MATERIALS AND METHODS: CAC scans of 30 consecutive patients (18 men and 12 women, age 70.1 ± 12.2 years) were reconstructed with FBP, HIR, and IMR, and the image noise was measured on all images. Two radiologists independently measured the CAC scores using semiautomated software, and interobserver agreement was evaluated. Statistical analysis included the Spearman correlation coefficient and Bland-Altman analysis. RESULTS: The mean image noise on FBP, HIR, and IMR images was 48.0 ± 7.9, 29.6 ± 4.8, and 9.3 ± 1.3 Hounsfield units, respectively. The difference among all reconstruction combinations was significant (P < .01). The CAC score on HIR and IMR scans was 4.2% and 8.9% lower, respectively, than the CAC score on FBP images. There was no significant difference in the mean CAC score among the three reconstructions. The interobserver correlation was excellent for all three reconstructions (r2 = 0.96 FBP, 0.99 HIR, 0.99 IMR); the best Bland-Altman measure of agreement was with IMR, followed by HIR and FBP. CONCLUSION: For CAC scoring, IMR can reduce the image noise and blooming artifacts, and consequently lowers the measured CAC score. IMR can lessen measurement variability and yield stable, reproducible measurements.

Effect of iterative reconstruction on variability and reproducibility of epicardial fat volume quantification by cardiac CT.

BACKGROUND: The epicardial fat volume (EFV) measured by cardiac CT has emerged as an important parameter for understanding the pathophysiology of coronary atherosclerosis. OBJECTIVE: We investigated the variability and reproducibility of EFV measurements and evaluated the effect of model-based type iterative reconstruction (M-IR) on measurement results. METHODS: Non-contrast cardiac CT data (tube voltage 120-kVp, tube current time product 32 mAs) of 30 consecutive patients were reconstructed with filtered back projection (FBP), hybrid type iterative reconstruction (H-IR), and M-IR using a slice thickness of 3.0 mm. CT attenuation and image noise was measured for all reconstructions. Two observers independently quantified EFV using semi-automated software and interobserver agreement was evaluated. RESULTS: There was no significant difference in the CT attenuation of the ascending aorta among the three reconstructions. The mean image noise on FBP-, H-IR-, and M-IR images was 48.0 ± 7.9 HU, 29.6 ± 4.8 HU, and 9.3 ± 1.3 HU, respectively; there was a significant difference among all comparison combinations for the three reconstructions (p < 0.01). FBP yielded the highest EFV among the three reconstructions (171.0 ± 54.9 cm(3) [FBP], 153.8 ± 53.1 cm(3) [H-IR], and 134.0 ± 46.4 cm(3) [M-IR]). For all three reconstructions, interobserver correlations were excellent (r = 0.91 [FBP], 0.93 [H-IR], and 0.96 [M-IR]). Interobserver comparisons showed that the lowest Bland-Altman limit of agreement was with M-IR (mean difference 2.0 ± 4.9%, 95% limit of agreement, -24.0 to 28.0%) followed by H-IR (-2.6 ± 7.1%, -39.8 to 34.6%) and FBP (-0.2 ± 8.6%, -45.3- to 45.0%). CONCLUSION: For the quantification of epicardial fat by cardiac CT, model-based iterative reconstruction can improve the image quality and lessen measurement variability.

256-Slice coronary computed tomographic angiography in patients with atrial fibrillation: optimal reconstruction phase and image quality.

OBJECTIVES: To assess the optimal reconstruction phase and the image quality of coronary computed tomographic angiography (CCTA) in patients with atrial fibrillation (AF). METHODS: We performed CCTA in 60 patients with AF and 60 controls with sinus rhythm. The images were reconstructed in multiple phases in all parts of the cardiac cycle, and the optimal reconstruction phase with the fewest motion artefacts was identified. The coronary artery segments were visually evaluated to investigate their assessability. RESULTS: In 46 (76.7 %) patients, the optimal reconstruction phase was end-diastole, whereas in 6 (10.0 %) patients it was end-systole or mid-diastole, and in 2 (3.3 %) patients it was another cardiac phase. In 53 (88.3 %) of the controls, the optimal reconstruction phase was mid-diastole, whereas it was end-systole in 4 (6.7 %), and in 3 (5.0 %) it was another cardiac phase. There was a significant difference between patients with AF and the controls in the optimal phase (p < 0.01) but not in the visual image quality score (p = 0.06). CONCLUSIONS: The optimal reconstruction phase in most patients with AF was the end-diastolic phase. The end-systolic phase tended to be optimal in AF patients with higher average heart rates. KEY POINTS: The optimal reconstruction phase in 76.7 % of patients with atrial fibrillation (AF) was end-diastole. The end-systolic phase was optimal in AF patients with higher heart rates. ECG and heart-rate control are necessary to obtain end-diastolic images with fewer motion artefacts.

Improved image quality at 256-slice coronary CT angiography in patients with a high heart rate and coronary artery disease: comparison with 64-slice CT imaging.

BACKGROUND: The 256-slice computed tomography (CT) scanners with wider detector coverage and faster gantry rotation speed are now available. The performance of scanners that feature a rotation speed of 270 ms at coronary CT angiography (CCTA) has not been evaluated in patients with a higher heart rate. PURPOSE: To evaluate the image quality of 256-slice CT with faster gantry rotation speed in patients undergoing CCTA. MATERIAL AND METHODS: We enrolled 886 patients; 357(40.3%) underwent study on a 64-slice CT at a rotation speed of 420 ms, the other 529 (59.7%) were examined using a 256-slice CT scanner at 270 ms. Two observers judged the image quality of 2658 imaged coronary arteries on a 4-point scale. RESULTS: The mean image quality score was significantly higher for the 256 - than the 64-slice CT scans (3.94 ± 0.28 vs. 3.73 ± 0.61; P < 0.01). There was no significant difference in the image quality scores between 64 - and 256-slice scans in patients whose heart rate (HR) was <60 bpm. However, in patients whose HR exceeded 60 bpm these scores were significantly higher for 256-slice CT images (P < 0.01). CONCLUSION: CCTA performed on the 256-slice CT scanner yielded significantly better image quality in patients with an HR exceeding 60 bpm.

A knowledge-based iterative model reconstruction algorithm: can super-low-dose cardiac CT be applicable in clinical settings?

RATIONALE AND OBJECTIVES: To investigate whether "full" iterative reconstruction, a knowledge-based iterative model reconstruction (IMR), enables radiation dose reduction by 80% at cardiac computed tomography (CT). MATERIALS AND METHODS: A total of 23 patients (15 men, eight women; mean age 64.3 ± 13.4 years) who underwent retrospectively electrocardiography-gated cardiac CT with dose modulation were evaluated. We compared full-dose (FD; 730 mAs) images reconstructed with filtered back projection (FBP) technique and the low-dose (LD; 146 mAs) images reconstructed with FBP and IMR techniques. Objective and subjective image quality parameters were compared among the three different CT images. RESULTS: There was no significant difference in the CT attenuation among the three reconstructions. The mean image noise of LD-IMR (18.3 ± 10.6 Hounsfield units [HU]) was significantly lowest among the three reconstructions (41.9 ± 15.3 HU for FD-FBP and 109.9 ± 42.6 HU for LD-FBP; P < .01). The contrast-to-noise ratio of LD-IMR was better than that of FD-FBP and LD-FBP (P < .01). Visual evaluation score was also highest for LD-IMR. CONCLUSIONS: The IMR can provide improved image quality at super-low-dose cardiac CT with 20% of the standard tube current.

Improved coronary in-stent visualization using a combined high-resolution kernel and a hybrid iterative reconstruction technique at 256-slice cardiac CT-Pilot study.

OBJECTIVES: To investigate the diagnostic performance of 256-slice cardiac CT for the evaluation of the in-stent lumen by using a hybrid iterative reconstruction (HIR) algorithm combined with a high-resolution kernel. METHODS: This study included 28 patients with 28 stents who underwent cardiac CT. Three different reconstruction images were obtained with: (1) a standard filtered back projection (FBP) algorithm with a standard cardiac kernel (CB), (2) an FBP algorithm with a high-resolution cardiac kernel (CD), and (3) an HIR algorithm with the CD kernel. We measured image noise and kurtosis and used receiver operating characteristics analysis to evaluate observer performance in the detection of in-stent stenosis. RESULTS: Image noise with FBP plus the CD kernel (80.2 ± 15.5 HU) was significantly higher than with FBP plus the CB kernel (28.8 ± 4.6 HU) and HIR plus the CD kernel (36.1 ± 6.4 HU). There was no significant difference in the image noise between FBP plus the CB kernel and HIR plus the CD kernel. Kurtosis was significantly better with the CD- than the CB kernel. The kurtosis values obtained with the CD kernel were not significantly different between the FBP- and HIR reconstruction algorithms. The areas under the receiver operating characteristics curves with HIR plus the CD kernel were significantly higher than with FBP plus the CB- or the CD kernel. The difference between FBP plus the CB- or the CD kernel was not significant. The average sensitivity, specificity, and positive and negative predictive value for the detection of in-stent stenosis were 83.3, 50.0, 33.3, and 91.6% for FBP plus the CB kernel, 100, 29.6, 40.0, and 100% for FBP plus the CD kernel, and 100, 54.5, 40.0, and 100% for HIR plus the CD kernel. CONCLUSIONS: The HIR algorithm combined with the high-resolution kernel significantly improved diagnostic performance in the detection of in-stent stenosis.

Incidence and risk factors of vascular complications following endovascular treatment of peripheral arterial disease via the popliteal artery.

To evaluate vascular complications associated with endovascular treatment (EVT) of peripheral arterial disease (PAD) through the popliteal artery and to identify the risk factors for these complications. Between November 2005 and January 2009, 63 patients with PAD received EVT via the popliteal artery. Retrograde (n = 58) and antegrade (n = 5) transpopliteal procedures were performed to target 77 lesions, including 12 distal to the trifurcation. Thirty-five punctures were performed under ultrasound guidance and 7 under angiographic guidance; 21 punctures were performed without any guidance. Vascular complications were evaluated by physical examination and duplex ultrasonography. Vascular complications at the popliteal puncture site occurred in 8 patients (12.7%): 6 hematomas and 2 arteriovenous fistulas (AVF). Seven of 24 patients receiving hemodialysis (HD) (29%) had significantly higher complications (P = 0.004) compared with 1 of 39 patients not receiving hemodialysis (non-HD) (2.6%). HD alone was also a significant risk factor for hematoma (P = 0.010). Both AVF occurred in HD patients (P = 0.141), and one occurred despite ultrasound-guided puncture. Ultrasound-guided puncture showed no significant improvement in reducing both complications. The combination of antiplatelet and anticoagulant therapy showed no statistical significance in overall complications. In non-HD patients, the transpopliteal approach in the EVT of PAD seems to be safe. More attention should be paid to HD patients when using the transpopliteal approach due to a higher complication rate.

PCI using a 4-Fr "child" guide catheter in a "mother" guide catheter: Kyushu KIWAMI® ST registry.

OBJECTIVES: With the development of PCI techniques, the indications for stents have been expanding as well. On the other hand, we often encounter the situations where deploying a stent/stents by the conventional method is technically challenging. We report a novel stent delivery system using a newly developed 4Fr. straight catheter with Mother-and-Child method. METHODS AND RESULTS: We collected the data on coronary angioplasty in which we experienced the difficulty to deliver coronary stents and used 4Fr. KIWAMI ST01. The case number amounts to 32 cases over a six-month period from October 2009 through March 2010. The angioplasty was performed for lesions in the RCA in 9 patients (28%), lesions in the LAD in 15 patients (47%), lesions in the LCX in 5 patients (16%), lesions in the saphenous vein grafts in 2 patients (6%), and lesions in the internal thoracic artery (LITA) grafts in 1 patient (3%). And the reasons for the difficult stent delivery by the conventional methods were as follows: severe calcification in 12 patients (37%), intense tortuosity in 7 patients (22%), poor backup support for guide catheter in 8 patients (25%), and trapping of the stent proximal to the target lesion in 5 patients (16%). The dislodgment of stent did not happened in all cases. CONCLUSIONS: KIWAMI® ST01 stent delivery system is feasible, safer, and effective in cases where stent delivery is difficult by the conventional method.

Low responsiveness to thienopyridine in hemodialysis patients.

We sought to evaluate whether thienopyridine low responsiveness, a predictor of stent thrombosis, is found in hemodialysis patients. We measured platelet aggregation at the site of implantation of drug-eluting stents in 333 patients with angina pectoris undergoing dual anti-platelet therapy. Thirty-one patients were on hemodialysis (HD group), and 302 were not (N-HD group). We used a novel whole-blood aggregometer. The aggregometer used the screen filtration method, with adenosine diphosphate as an agonist. The concentration of agonist required to induce 50% of the maximum pressure rate was calculated and indicated as the platelet aggregatory threshold index (PATI). Low responsiveness for thienopyridine was defined if the PATI levels were <4 µmol/l. PATI levels (µmol/l) were significantly lower in the HD group than in the N-HD group (6.8 ± 4.8 vs. 9.1 ± 5.4, P = 0.023), and the rate of low responsiveness for thienopyridine was significantly higher in the HD group than in the N-HD group (45.7 vs. 26.8%, P = 0.019). Non-fatal myocardial infarction and stent thrombosis occurred in three of the HD group and in nine of the N-HD group (P = 0.122). Late stent thrombosis occurred at a significantly higher rate in the HD group than in the N-HD group (P = 0.002). The rate of target lesion revascularization was significantly higher in the HD group than in the N-HD group (38 vs. 11.8%, P = 0.0001). In conclusion, low responsiveness to thienopyridine, as an indicator of platelet reactivity, is found more frequently in hemodialysis patients.

Sorafenib-induced acute myocardial infarction due to coronary artery spasm.

A 65-year-old man with advanced renal cell carcinoma was admitted due to continuing chest pain at rest. Two weeks before his admission, sorafenib had been started. He was diagnosed with non-ST-elevation myocardial infarction by laboratory data and electrocardiogram. Enhanced heart magnetic resonance imaging also showed subendocardial infarction. However, there was no stenosis in coronary arteries on angiography. Coronary artery spasm was induced by a provocative test. Cessation of sorafenib and administration of Ca-channel blocker and nitrates ameliorated his symptoms, but relapse occurred after resumption of sorafenib. Addition of oral nicorandil reduced his symptoms and maintained stable angina status. We report the first case of sorafenib-induced coronary artery spasm. Sorafenib is a multikinase inhibitor that targets signaling pathways necessary for cellular proliferation and survival. On the other hand, the Rho/ROCK pathway has an important role in the pathogenesis of coronary artery spasm. Our report may show an adverse effect on the Rho/ROCK pathway by sorafenib use.

Effects of gastric medicines on gastroduodenal injury in patients with stable angina during antiplatelet therapy.

BACKGROUND: The aim of this study was to examine the effects of gastric medicines on gastroduodenal injury during antiplatelet therapy after coronary intervention. METHODS: A total of 501 patients were enrolled and as dual antiplatelet therapy, aspirin and thienopyridine were administered. Patients were divided into four groups: histamine H2-receptor antagonists (H2RA); proton pump inhibitors (PPI); other gastromucosal protective agents (GMP); or nothing (None), and follow-up lasted 8-20 months. RESULTS: H2RA were prescribed in 212 cases (42%), PPI in 150 (30%), GMP in 56 (11%), and None in 83 (17%). Significant findings by endoscopy were recognized in 18 cases and upper gastrointestinal bleeding requiring hospitalization occurred in 7 patients (1.4%; H2RA in 4, GMP in 2, and None in 1). There were no gastrointestinal injuries in the PPI group. To minimize the effect of selection bias on gastroduodenal lesions, the propensity score analysis for clinical characteristics was used. The results of propensity score matching showed that administration of PPI reduced the incidence of gastrointestinal lesions compared with that of the non-PPI group. CONCLUSION: Administration of PPI reduced the incidence of gastrointestinal lesions compared with that of the non-PPI group.

Metal allergic reaction in chronic refractory in-stent restenosis.

OBJECTIVES: This study examined the relationship between chronic refractory (CR) in-stent restenosis (ISR) and metal allergic reaction. BACKGROUND: Although drug-eluting stent reduced the restenotic event compared with bare-metal stent, the mechanism of neointimal proliferation is not clear yet; however, bare-metal stent still remains as one of the choices. METHODS: Of 128 bare-metal stent implanted patients who experienced target lesion revascularization at least once, 60 patients with the second ISR (study group) and 68 patients without the second ISR (control group) were compared in terms of result from the skin patch test for metal allergic reaction. RESULTS: Nickel was dominant among components of 316L stainless steel. The nickel-positive was observed in 19% (24/128) of all patients. Of 24 nickel-positive, 18 (30%) was in the study group, whereas 6 (9%) was in the control group (P=.02). According to multivariate analysis, the most significant predictor for CR-ISR was reference vessel diameter (P=.0010) followed by nickel-positive (P=.0033) and hyperlipidemia (P=.0305). The nickel-positive showed the highest odds ratio of 5.41 adjusted with confounder variables. CONCLUSION: This study with the second ISR showed that nickel was a major factor for CR-ISR. Further improvement of biocompatible material is required for coronary stents and strut-coating materials even in the drug-eluting stent era.

Subacute thrombosis after coronary stenting occurring with resistance to ticlopidine.

A 79-year-old man underwent stent implantation from the proximal site to the left main trunk with one bare metal stent after rotation atherectomy. He received 200 mg/day ticlopidine and 200 mg/day aspirin from 2 days pre-stenting. Subacute thrombosis occurred 5 days after coronary stenting. We performed a test of platelet aggregation one month after the commencement of dual antiplatelet therapy and the test showed no response to ticlopidine in this case. An increased dose of ticlopidine was not effective for suppressing platelet aggregation. We report a case of subacute stent thrombosis which is related to ticlopidine resistance.

Increased expression of monocyte chemoattractant protein-1 in atherectomy specimens from patients with restenosis after percutaneous transluminal coronary angioplasty.

The plasma concentration of monocyte chemoattractant protein-1 (MCP-1) antigen is higher in patients with restenosis after coronary angioplasty than in those who do not restenose. In this study the MCP-1 expression of coronary atherectomy specimens was investigated by immunohistochemistry. Samples were obtained from 12 patients with restenosis and 15 with de novo lesions by directional coronary atherectomy. MCP-1 immunoreactivity was found in all patients in the restenosis group and in 8 of the de novo group. The frequency of macrophage expression was higher in the restenosis group than in de novo group. These results indicate that local expression of MCP-1 may be associated with the mechanisms of vascular remodeling after coronary angioplasty.