Ectopic Breast Cancer Arising within an Axillary Lymph Node.

We report our experience with the diagnosis and treatment of an ectopic breast cancer arising within an axillary lymph node. The patient was a 65-year-old woman diagnosed breast cancer and axillary lymph node metastasis. We performed a partial mastectomy and axillary lymph node dissection. Postoperative pathology revealed no malignant lesions in the breast; however, a nodule in one of axillary lymph nodes had mixed benign and malignant components, leading to a diagnosis of invasive ductal carcinoma derived from ectopic mammary tissue. This case represents a very rare form of breast cancer, and the malignancy was difficult to distinguish from metastasis.

Efficacy and impact of SARS-CoV-2 vaccination on cancer treatment for breast cancer patients: a multi-center prospective observational study.

PURPOSE: Vaccination is an essential strategy to prevent infection in the SARS-CoV-2 pandemic. However, there are concerns about vaccine efficacy and the impact of vaccination on cancer treatment. Additionally, the emergence of novel variants may affect vaccination efficacy. This multi-center, prospective, observational study investigated the efficacy and impact of vaccination against SARS-CoV-2 variants on treatment among breast cancer patients in Japan. METHODS: Patients with breast cancer scheduled to be vaccinated with the SARS-CoV-2 vaccine from May to November 2021 were prospectively enrolled (UMIN000045527). They were stratified into five groups according to their cancer treatment: no treatment, hormone therapy, anti-human epidermal growth factor receptor (HER)2 therapy, chemotherapy, and cyclin-dependent kinase 4/6 (CDK4/6) inhibitor. Serum samples for assessing serological responses were collected before the first vaccination and after the second vaccination. RESULTS: Eighty-five breast cancer patients were included. The overall seroconversion rate after second vaccination was 95.3% and the lowest seroconversion rate was 81.8% in the patients under chemotherapy. The overall positivity rate of neutralizing antibodies against the wild-type, α, Δ, κ, and omicron variants were 90.2%, 81.7%, 96.3%, 84.1%, and 8.5%, respectively. Among the patients under chemotherapy or CDK4/6 inhibitors, various degrees of decreased neutralizing antibody titers against SARS-CoV-2 variants were observed. Withdrawal or reduction of systemic therapy because of vaccination was observed in only one patient. CONCLUSION: Our data support SARS-CoV-2 vaccination for breast cancer patients. However, a reduction in neutralizing antibody titers was suggested during chemotherapy and CDK4/6 inhibitors, raising concerns about the impact on long-term infection prevention.

YES1 as a Therapeutic Target for HER2-Positive Breast Cancer after Trastuzumab and Trastuzumab-Emtansine (T-DM1) Resistance Development.

Trastuzumab-emtansine (T-DM1) is a therapeutic agent molecularly targeting human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC), and it is especially effective for MBC with resistance to trastuzumab. Although several reports have described T-DM1 resistance, few have examined the mechanism underlying T-DM1 resistance after the development of acquired resistance to trastuzumab. We previously reported that YES1, a member of the Src family, plays an important role in acquired resistance to trastuzumab in HER2-amplified breast cancer cells. We newly established a trastuzumab/T-DM1-dual-resistant cell line and analyzed the resistance mechanisms in this cell line. At first, the T-DM1 effectively inhibited the YES1-amplified trastuzumab-resistant cell line, but resistance to T-DM1 gradually developed. YES1 amplification was further enhanced after acquired resistance to T-DM1 became apparent, and the knockdown of the YES1 or the administration of the Src inhibitor dasatinib restored sensitivity to T-DM1. Our results indicate that YES1 is also strongly associated with T-DM1 resistance after the development of acquired resistance to trastuzumab, and the continuous inhibition of YES1 is important for overcoming resistance to T-DM1.

Follicular cholangitis mimicking cholangiocarcinoma treated with right hepatectomy: A case report and review of published works.

Follicular cholangitis is a new, rare disease that causes severe biliary stricture. We herein describe the findings from a resected case of follicular cholangitis, suggesting a distinct disease entity that causes benign biliary stricture. A 60-year-old man who was referred to our hospital due to elevated γ-glutamyl transpeptidase levels and dilatation of the B8 bile duct. Although bile juice cytology and bile duct brushing cytology showed no malignancy, the dilatation was progressive. Therefore, right hepatectomy combined with caudate lobectomy was carried out on suspicion of intrahepatic cholangiocarcinoma. The wall of the resected bile duct was markedly thickened due to severe fibrosis under the mucosal layer. Histology of the mucosal epithelium indicated no malignancy. Infiltration of plasma cells characterized by remarkable formation of lymphoid follicles with germinal centers was observed around the bile ducts. The patient was diagnosed with follicular cholangitis based on histological findings. We thus observed a rare case of follicular cholangitis. This case and review of published reports suggest that, despite its rarity, follicular cholangitis should be considered at the differential diagnosis of biliary stricture. This case report could contribute to a better understanding of how to address this disease.

[A Resected Case of Reactive Lymphoid Hyperplasia of the Liver Preoperatively Diagnosed as Hepatocellular Carcinoma].

A60s woman was followed-up regularly for primary biliary cholangitis and a solitary enlarging hepatic mass in the S6 segment of her liver was discovered by ultrasonography. We diagnosed the mass as hepatocellular carcinoma by contrast ultrasonography, contrast computed tomography, and ethoxbenzyl magnetic resonance imaging and laparoscopic partial hepatectomy of S6 segment was performed. The resected specimen was histopathologicaly diagnosed as liver-reactive lymphoid hyperplasia(RLH). The patient is alive without recurrence 17 months after the surgery. Although liver RLH is a rare disease, it should be considered in the differential diagnosis of small liver tumors.

[Long-Term Survival after Surgical Treatment of Neuroendocrine Carcinoma of the Ampulla of Vater-A Case Report].

A 60s man underwent upper gastrointestinal endoscopy at a regular medical check-up without symptoms, which showed an ulcerative region in the duodenal ampulla, measuring 3 cm in diameter. He was diagnosed with poorly differentiated adenocarcinoma on biopsy and referred to our hospital. Abdominal contrast-enhanced CT scan revealed an enhanced-ulcerative tumor, measuring 3 cm, at the duodenal ampulla. After the preoperative diagnosis of adenocarcinoma of the duodenal ampulla, subtotal stomach-preserving pancreatoduodenectomy with regional lymph node dissection was performed. The final diagnosis was neuroendocrine carcinoma(NEC)of the duodenal ampulla. He has been alive for 9 years with no recurrences. NEC of the duodenal ampulla is rare, and its prognosis is poor. We report a case of long-term survival after resection of NEC of the duodenal ampulla.

Current Multidisciplinary Approach to Fertility Preservation for Breast Cancer Patients.

Adverse effects on fertility are a significant problem for premenopausal breast cancer patients. Since April 2009, we have been referring young patients for fertility counseling provided by a multidisciplinary team. Here we evaluated the efficacy and safety of our current fertility preservation approach. We retrospectively analyzed the cases of 277 patients < 45 years old at diagnosis, which was made between 2009 and 2016. Seventy-two (26%) patients received fertility counseling. Seventeen (6%) of the 277 patients decided to preserve their fertility before starting adjuvant systemic therapy. Six (35%) patients underwent oocyte cryopreservation, and 11 (65%) married patients opted for embryo cryopreservation. There were no pregnancies among the patients undergoing oocyte cryopreservation, whereas 3 (27%) of the patients who opted for embryo cryopreservation became pregnant. Two (12%) patients stopped endocrine therapy after 2 years in an effort to become pregnant, but their breast cancers recurred. Though the problem of fertility loss for breast cancer patients is important and we should assess the infertility risk for all patients, we should also consider the prognosis. In June 2016, we launched a prospective multicenter cohort study to evaluate the efficacy and safety of fertility preservation in greater detail.

[A Case of Unresectable Advanced Gastric Neuroendocrine Cell Carcinoma Treated with Nivolumab].

A 69-year-old man was administered S-1/oxaliplatin/trastuzumab as induction chemotherapy for advanced gastric cancer (cT4b[liver, pancreas], N2M1(H1P0CYX), cStage IV). After 4 courses, because contrast-enhanced computed tomography showed remarkable reduction of the tumor, distal gastrectomy, partial hepatectomy, and radiofrequency ablation for the liver metastasis were performed. The patient was histopathologically diagnosed with gastric neuroendocrine carcinoma(NEC). S- 1/oxaliplatin/trastuzumab was continued after surgery; however, recurrence in the remnant liver was observed after 4 cours- es. For recurrence, cisplatin/irinotecan as first-line and paclitaxel/ramucirumab as second-line treatment were administered, but progression of liver metastasis and ascites due to peritoneal dissemination were observed. As third-line treatment, nivolumab was initiated. Ascites decreased after 3 courses, but after 2 more courses, progression of ascites, liver recurrence, and multiple metastasis in the lumbar vertebra were observed.

[A Resected Case of Intraductal Pupillary Mucinous Neoplasm of the Pancreas Characterized by Recurrence in the Remnant Pancreas and Multiple Malignant Neoplasms in Other Organs].

A 74-year-old man underwent pancreaticoduodenectomy for intraductal pupillary mucinous neoplasm(IPMN)of the pancreatic head. Histopathological examination of the specimen revealed non-invasive intraductal papillary mucinous carcinoma( IPMC). Two years after surgery, recurrent IPMN developed in the remnant pancreas, and a liver tumor was identified in S8 of the liver. The patient underwent total pancreatectomy of the remnant pancreas and partial resection of S8. These tumors were histopathologically diagnosed as invasive IPMC and hepatocellular carcinoma, respectively. Five years after the resec- tions, another liver tumor was identified in S4/3 of the liver, and partial resection of S4/3 was performed. The tumor was histopathologically identified as cholangiocellular carcinoma. Seven months after the last surgery, the patient remains in good health without any recurrences. IPMN is characterized by IPMN recurrence in the remnant pancreas and malignant neoplasms in other organs, and the present case showed both characteristics. The case suggested the importance of postoperative follow-up of IPMN patents with regard to the characteristics of IPMN.

Measuring serum and drainage fluid interleukin-6 and tumor necrosis factor-α levels for early detection of infectious complications after minimally invasive surgery for gastric cancer.

OBJECTIVE: Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) are inflammatory cytokines produced in response to biological invasion or infection. Their levels are elevated in the blood and locally. We examined whether measuring IL-6 and TNF-α levels in serum or drainage fluid on postoperative day (POD) 1 could detect infectious complications after minimally invasive surgery for gastric cancer. METHODS: This cohort study included 205 consecutive patients who underwent laparoscopic or robot-assisted gastrectomy for gastric cancer between November 2020 and July 2023. We measured serum and drainage fluid IL-6 and TNF-α levels on POD 1 after gastrectomy. Receiver operating characteristic (ROC) curves were created to compare the diagnostic values of each cytokine and serum C-reactive protein levels for detecting postoperative infectious complications. RESULTS: IL-6 and TNF-α levels in the serum or drainage fluid were significantly higher in patients with an infectious complication. In addition, drainage fluid IL-6 levels were significantly different in patients with versus without intra-abdominal abscess. In the ROC curve analysis, serum and drainage fluid IL-6 had the highest AUC values for any infectious complication and intra-abdominal abscess, respectively. POD 1 serum IL-6 level above 47 pg/mL could detect any infectious complication with sensitivity of 74.1 % and specificity of 71.8 %. POD 1 drainage fluid IL-6 level above 14,750 pg/mL had 100 % sensitivity for detecting intra-abdominal abscess with specificity of 56.0 %. CONCLUSIONS: Measurement of IL-6 levels in blood and drainage fluid on POD 1 is valuable for early detection of postoperative infectious complications or intra-abdominal abscess after gastric cancer surgery.

Phase 2 trial of neoadjuvant docetaxel, oxaliplatin, and S-1 for clinical stage III gastric or esophagogastric junction adenocarcinoma.

Background: Although perioperative treatment has been the standard of care for resectable gastric cancer in the West, postoperative adjuvant chemotherapy is still the standard in Japan. We conducted the first phase 2 trial to investigate the efficacy and safety of neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) chemotherapy for cStage III gastric or esophagogastric junction (EGJ) adenocarcinoma in Japan. Methods: Eligibility criteria included cStage III adenocarcinoma of the stomach or EGJ. Patients received docetaxel (40 mg/m2, day 1), oxaliplatin (100 mg/m2, day 1), or S-1 (80 mg/m2, days 1-14) during a 3-week cycle. After two or three cycles of DOS, patients underwent surgical resection. The primary endpoint was progression-free survival (PFS). Results: Between June 2015 and March 2019, 50 patients were enrolled from four institutions. Of 48 eligible patients (37 gastric and 11 EGJ adenocarcinoma), 42 (88%) completed two or three DOS cycles. Grade 3-4 neutropenia and diarrhea occurred in 69% and 19% of patients, respectively, but there were no treatment-related deaths. R0 resection was achieved in 44 (92%) patients, and the pathological response rate (≥ grade 1b) was 63% (30/48). The 3-year PFS, overall survival, and disease-specific survival rates were 54.2%, 68.7%, and 75.8%, respectively. Conclusion: Neoadjuvant DOS chemotherapy had a sufficient antitumor effect and tolerable safety profile in patients with gastric or EGJ adenocarcinoma. The survival benefit of a neoadjuvant strategy using our DOS regimen should be validated in phase 3 trials.

Association between home-based exercise using a pedometer and clinical prognosis after endovascular treatment in patients with peripheral artery disease.

BACKGROUND: Exercise therapy following endovascular treatment (EVT) is important for patients with peripheral artery disease (PAD); however, continuous exercise therapy is difficult to be performed in clinical practice. This study aimed to investigate the association between the implementation of home-based exercise using pedometers after EVT and 1-year clinical outcomes. METHODS: This multicenter observational prospective cohort registry included patients with PAD complaining of intermittent claudication who underwent EVT for aortoiliac and/or femoropopliteal artery lesions between January 2016 and March 2019. Patients were instructed to perform home-based exercises using a specific pedometer after EVT. The study population was divided into good and poor recording groups according to the frequency of the pedometer measurements. The good recording group was defined as those who completed ≥50 % of the prescribed daily pedometer recording during the follow-up period. The poor recording group was defined as those with an inability to use a pedometer and/or who completed <50 % of the prescribed daily pedometer recordings. The primary outcome was 1-year major adverse events (MAE), defined as a composite of all-cause death, non-fatal myocardial infarction, non-fatal stroke, target vessel revascularization, and major amputation of the target limb. RESULTS: The mean age was 74.4 years; 78 % were male. A total of 623 lesions were analyzed (58.7 % aortoiliac, 41.3 % femoropopliteal). At 1 year, a lower cumulative incidence of MAE was observed in the good recording group compared to that in the poor recording group [10/233 (4.3 %) vs. 35/267 (13.7 %) patients, respectively; p < 0.001]. Multivariate Cox regression analysis showed that patients in the good recording group had a lower hazard ratio for 1-year MAE (0.33; 95 % confidence interval, 0.16-0.68; p = 0.004) than that in the poor recording group. CONCLUSIONS: Good self-recording of pedometer measurements was associated with favorable prognosis in patients with PAD following EVT.

Comparison of the effects of nitroprusside versus nicorandil on the slow/no-reflow phenomenon during coronary interventions for acute myocardial infarction.

Although slow/no-reflow is a serious problem complicating primary percutaneous coronary interventions (PCI) for acute myocardial infarction (AMI) and is associated with a poor prognosis, its efficacious treatment remains problematic. We compared the acute, in-hospital and long-term (1 year) effects of nitroprusside (NTP) with those of nicorandil (NC) on the slow/no-reflow phenomenon. Forty-nine of 442 consecutive patients with AMI who underwent primary PCI complicated by slow/no-reflow and who received intracoronary NTP (n = 25) or NC (n = 24) administration were studied. Both NTP and NC induced significant improvements in coronary flow, with increases in TIMI flow grade from 1.64 ± 0.62 to 2.74 ± 0.36 (p < 0.001) and 1.60 ± 0.86 to 2.23 ± 0.91 (p < 0.001), and in corrected TIMI frame count from 37.8 ± 15.1 to 13.7 ± 7.1 (p < 0.001) and 30.8 ± 20.7 to 19.3 ± 17.9 (p < 0.001), respectively. The degree of improvement in TIMI flow grade (post-pre/pre) and TIMI frame count (pre-post/pre) showed that NTP was more effective than NC (NTP vs. NC: 0.88 ± 0.79, 0.37 ± 0.37, p = 0.008; 0.59 ± 0.23, 0.36 ± 0.27, p = 0.003, respectively). Congestive heart failure did not tend to last beyond 3 days after onset in the NTP group, which was more than in the NC group, during hospitalization (1/25, 4/24, p = 0.143, respectively). At the 1-year follow-up, the NTP group tended to show more improvement than the NC group in MACE (5/25, 9/24, p = 0.175, respectively). NTP is a more effective treatment for slow/no-reflow associated with PCI in patients with AMI and may improve long-term clinical outcomes compared with NC.

Effect of Target Lesion Revascularization on Restenosis Lesions of the Superficial Femoral Artery without Recurred Symptoms after Endovascular Therapy.

AIM: This study aims to elucidate the effects of early application of target lesion revascularization (TLR) to restenosis lesions of the superficial femoral artery (SFA) without recurrence of symptoms. Despite recent improvements in endovascular therapy (EVT) for the SFA, restenosis remains to be a problem. However, restenosis is not always associated with the recurrence of limb symptoms. Although early application of TLR is not generally approved for restenosis lesions of the SFA without recurred symptoms, it is expected to contribute to long-term patency and other favorable outcomes. Nonetheless, its effectiveness remains to be determined. METHODS: We retrospectively analyzed 616 patients who developed restenosis after undergoing femoro-popliteal EVT for claudication (Rutherford category 1 to 3) due to de novo femoro-popliteal lesions between January 2010 and December 2016 at 11 centers in Japan. Recurred symptoms were defined as symptoms of the same or higher Rutherford categories than those immediately before the initial EVT. RESULTS: Of the patients, 291 (47 %) lacked recurred symptoms; 69 (24 %) underwent TLR for restenosis. After propensity matching, the risk of occlusion was determined to be not significantly different between the TLR and observation groups; the 3-year occlusion-free rate was 68 % and 62 %, respectively (P=0.84). The risk of recurring symptoms, critical limb ischemia, and all-cause death was also found to be comparable between groups. The incidence of target vessel revascularization was significantly higher in the TLR than in the observation group (1.55 [95 % confidence interval: 1.25-1.93] vs. 0.59 [0.41-0.85] per 3 person-years). CONCLUSIONS: In patients with SFA restenosis without recurred symptoms, early application of TLR showed no advantages.

Predictive Value of the Cardio-Ankle Vascular Index for Cardiovascular Events in Patients at Cardiovascular Risk.

Background Arterial stiffness is an important predictor of cardiovascular events; however, indexes for measuring arterial stiffness have not been widely incorporated into routine clinical practice. This study aimed to determine whether the cardio-ankle vascular index (CAVI), based on the blood pressure-independent stiffness parameter ß and reflecting arterial stiffness from the origin of the ascending aorta, is a good predictor of cardiovascular events in patients with cardiovascular disease risk factors in a large prospective cohort. Methods and Results This multicenter prospective cohort study, commencing in May 2013, with a 5-year follow-up period, included patients (aged 40‒74 years) with cardiovascular disease risks. The primary outcome was the composite of cardiovascular death, nonfatal stroke, or nonfatal myocardial infarction. Among 2932 included patients, 2001 (68.3%) were men; the mean (SD) age at diagnosis was 63 (8) years. During the median follow-up of 4.9 years, 82 participants experienced primary outcomes. The CAVI predicted the primary outcome (hazard ratio, 1.38; 95% CI, 1.16‒1.65; P<0.001). In terms of event subtypes, the CAVI was associated with cardiovascular death and stroke but not with myocardial infarction. When the CAVI was incorporated into a model with known cardiovascular disease risks for predicting cardiovascular events, the global χ2 value increased from 33.8 to 45.2 (P<0.001), and the net reclassification index was 0.254 (P=0.024). Conclusions This large cohort study demonstrated that the CAVI predicted cardiovascular events. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01859897.

Stentless treatment strategy for left circumflex artery ostial stenosis: Directional coronary atherectomy followed by drug-eluting balloon.

A 60-year-old man with history of exertional angina pectoris was referred for treatment of an ostial left circumflex (LCX) coronary artery stenosis. The branch angle between left anterior descending artery (LAD) and LCX was shallow, therefore stent implantation seemed at risk of "carina shift" of plaque to the LAD ostium as well as higher in-stent restenosis. Therefore, directional coronary atherectomy (DCA, Atherocut™, L-size, NIPRO, Osaka, Japan) was performed at the ostium of the LCX lesion. After evaluating plaque accumulation using intravascular ultrasound (IVUS), DCA was circumferentially performed 16 times, from 2 atm to 3 atm, using an 8 fr guide system. Although angiogram and IVUS showed excellent results, adjunctive balloon dilatation with 3.5 mm paclitaxel-coated balloon was performed to prevent restenosis. At 8 months, the patient reported being angina-free, and subsequent follow-up angiogram showed no restenosis of LCX. Paclitaxel-coated balloon following DCA for LCX ostial stenosis seems to be safe and effective for both acute and chronic results, suggesting a potential stentless therapeutic option. .

The "Off-Hour Effect" in Urgent Laparoscopic Cholecystectomy for Acute Cholecystitis.

BACKGROUND: The observation that patients may have worse outcomes after urgent therapeutic interventions performed during off-hours compared with on-hours is termed the "off-hour effect." This phenomenon has not been examined in urgent laparoscopic cholecystectomy (LC). Here we aimed to investigate the off-hour effect in urgent LC for acute cholecystitis. PATIENTS AND METHODS: This study enrolled patients who underwent urgent LC for acute cholecystitis at our institution. On-hour LC was defined as a weekday operation starting between 9 AM and 9 PM; and off-hour LC as an operation on a weekend, or starting between 9 PM and 9 AM on a weekday. Patients were divided into on-hour and off-hour groups, and the operative outcomes of LC were compared between these groups. RESULTS: The study included 371 patients, with 270 (72.8%) on-hour, and 101 (27.2%) off-hour operations. The 2 groups did not significantly differ in operation time, intraoperative blood loss, conversion rate to open surgery, incidence of postoperative complications, or duration of postoperative hospital stay. DISCUSSION: Operative outcomes of urgent LC were comparable between the on-hour and off-hour groups, suggesting that there was no significant off-hour effect in urgent LC.

Clinical characteristics of responders to treatment with tolvaptan in patients with acute decompensated heart failure: Importance of preserved kidney size.

BACKGROUND: Recent clinical trials have demonstrated the efficacy of short-term treatment with tolvaptan, an oral vasopressin V2 receptor antagonist, in patients with heart failure. However, the response to tolvaptan varies among patients. The aim of this study was to determine factors associated with response to tolvaptan in patients with acute decompensated heart failure (ADHF). METHODS: The Tolvaptan Registry, a prospective, observational, multicenter cohort study performed in Japan, aims to determine factors affecting the responsiveness of tolvaptan in patients with ADHF. We enrolled ADHF patients treated with tolvaptan and they were divided into two groups: responders and non-responders. Responders were defined as subjects who met all of the following three conditions: (1) increasing urine volume during a 24-hour period after the start of tolvaptan treatment; (2) improvement in New York Heart Association functional class; and (3) decrease in cardiothoracic ratio assessed by chest X-ray on day 3 of tolvaptan administration. RESULTS: Among the 114 patients, treatment with tolvaptan improved three conditions of heart failure in more than half of all the cohorts (71 patients, 62%). As for baseline characteristics, estimated glomerular filtration rate, urine osmolality, and kidney size were significantly greater in responders than in non-responders. Multivariate logistic analysis revealed that kidney size was independently associated with responders (odds ratio: 1.083, p=0.001, 95% confidence interval 1.031-1.137). CONCLUSIONS: The main clinical characteristic of responders to treatment with tolvaptan is that kidney size is preserved.

Nicorandil prevents microvascular dysfunction resulting from PCI in patients with stable angina pectoris: a randomised study.

AIMS: Nicorandil, an ATP sensitive potassium channel opener, may reduce the incidence of microvascular dysfunction after percutaneous coronary intervention (PCI) by dilating coronary resistance vessels. The aim of the study was evaluation of the impact of the administration of intravenous nicorandil on measuring the index of microcirculatory resistance (IMR) in PCI to patients with stable angina pectoris (SAP). METHODS AND RESULTS: Intravascular ultrasound (IVUS), fractional flow reserve (FFR), IMR and blood examination (CK-MB), cardiac troponin I (cTnI) immediately post-PCI (and 24 hours later) were performed in 62 consecutive patients with SAP undergoing PCI. FFR and IMR were measured simultaneously with a single coronary pressure wire. IMR was defined as Pd/coronary flow (or Pd* mean transit time) at peak hyperaemia. Patients were randomised to the control (n=29), or nicorandil group (n=33). In the nicorandil group, nicorandil was intravenously administered as a 6 mg bolus injection just before PCI and as a constant infusion at 6 mg/hour for 24 hours thereafter. All volumetric IVUS parameters and FFR were similar between the two groups both pre- and post-PCI. However, IMR immediately post-PCI and cTnI 24 hours post-PCI were significantly higher in the control group compared to the nicorandil group (IMR: 25.4±12.1 vs. 17.9±9.1 units, and cTnI: 0.21±0.13 vs. 0.12±0.08 ng/mL, for control vs. nicorandil). The incidence for cTnI elevation more than fivefold the normal range (>0.20 ng/mL) was significantly larger in the control group than in the nicorandil group (41% vs. 12%, p<0.01). Additionally, the control group showed a closer correlation between plaque volume reduction during stenting as assessed by volumetric IVUS, and cTnI elevation than the nicorandil group (r=0.55 vs. 0.42, p<0.001 for control vs. nicorandil). CONCLUSIONS: In patients undergoing successful coronary stenting for stable angina, administration of nicorandil is associated with reduced microvascular dysfunction induced by PCI.