[HIS bundle pacing : Far more than an ECG cosmetic effect]

The therapy for heart failure in patients with uncompromised systolic ventricular function (HfpEF) is still challenging because there is an obvious lack of effective therapy options. Several of these particular patients are additionally presenting atrioventricular (AV) block. In these patients HIS bundle pacing could be a hopeful therapy strategy due to the option of an AV resynchronisation as illustrated in the following case.

Abstract A043: Discovery to first-in-man studies of a multi-peptide-based hepatocellular carcinoma vaccine adjuvanted with CV8102 (RNAdjuvant®): HEPAVAC

Hepatocellular (HCC)/normal adjacent tissue matched samples have been collected for HLA immunopeptidome analysis. 17 HCC samples from HLA-A*02+ patients and 15 samples from HLA-A*24+ patients have been analysed by mass spectrometry (LC-MS/MS). RNA-expression profiles have been established for 12 HCC samples. HLA-presentation/expression of peptides on primary HCC samples (as well as mRNA expression) were compared to normal tissue samples from relevant organs (including heart, brain, lung, kidney, liver, nerve, skin etc.) present in the Immatics' database. A total of 16 peptides have been selected and confirmed for immunogenicity for the HepaVac vaccine and are currently synthesized according to GMP standard. Of these, 7 are restricted to HLA-A*02; 5 to HLA-A*24 and 4 to HLA class II. Formulation development studies have been undertaken leading to a suitable and stable pharmaceutical form. An analytical method was developed which allows the characterization of each individual peptide within the HepaVac vaccine (IMA970A). At present, preclinical studies assessing the combination of the immunological RNA-based adjuvant (RNAdjuvant®) with the peptide-based HepaVac vaccine IMA970 are conducted. A single-arm, first-in-man trial entitled HepaVac-101 is designed to investigate in patients with very early, early and intermediate stage of HCC the off-the-shelf multi-peptide-based HCC vaccine (IMA970) plus the CV8102 adjuvant (RNAdjuvant®) following a single pre-vaccination infusion of low-dose cyclophosphamide acting as an immunomodulator. The study drugs are applied without concomitant anti-tumor therapy with the intention to reduce risk of tumor recurrence/progression in patients who have received all indicated standard treatments. The primary endpoints are safety, tolerability, and immunogenicity. Secondary/exploratory endpoints are additional immunological parameters in blood (e.g. regulatory T-cells, myeloid-derived suppressor cells, impact of the standard therapy on the natural immune response), infiltrating T-lymphocytes in tumor tissue, biomarkers in blood and tissue, disease-free survival/progression-free survival and overall survival. Once safety of this vaccination approach has been determined in the first 10-20 patients the addition of a checkpoint inhibitor will be considered. Suitable patients enrolled in Tuebingen are invited to participate in a trial extension investigating an actively personalized vaccine (APVAC) plus CV8102. The HepaVac project started in September 2013 and is supported by the European Commission's 7th Framework Program under the Grant Agreement Nr. 602893 (www.hepavac.eu). The clinical trial HepaVac-101 will be conduct in 6 centers located in 5 European countries, i.e. Italy (Naples and Varese), Germany (Tübingen), UK (Birmingham), Spain (Pamplona) and Belgium (Antwerpen).

Citation Format: Andrea Mayer-Mokler, Roberto Accolla, Yuk T. Ma, Regina Heidenreich, Francesco Izzo, Alfred Koenigsrainer, Markus Loeffler, Christian Flohr, Phillip Mueller, Sarah Kutscher, Hans-Georg Rammensee, Bruno Sangro, Sven Francque, Danila Valmori, Toni Weinschenk, Carsten Reinhardt, Ulrike Gnad-Vogt, Harpreet Singh, Luigi Buonaguro. Discovery to first-in-man studies of a multi-peptide-based hepatocellular carcinoma vaccine adjuvanted with CV8102 (RNAdjuvant®): HEPAVAC [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A043.

A Cancer Research UK First Time in Human Phase I Trial of IMA950 (Novel Multipeptide Therapeutic Vaccine) in Patients with Newly Diagnosed Glioblastoma

PURPOSE

To perform a two-cohort, phase I safety and immunogenicity study of IMA950 in addition to standard chemoradiotherapy and adjuvant temozolomide in patients with newly diagnosed glioblastoma. IMA950 is a novel glioblastoma-specific therapeutic vaccine containing 11 tumor-associated peptides (TUMAP), identified on human leukocyte antigen (HLA) surface receptors in primary human glioblastoma tissue.

EXPERIMENTAL DESIGN

Patients were HLA-A*02-positive and had undergone tumor resection. Vaccination comprised 11 intradermal injections with IMA950 plus granulocyte macrophage colony-stimulating factor (GM-CSF) over a 24-week period, beginning 7 to 14 days prior to initiation of chemoradiotherapy (Cohort 1) or 7 days after chemoradiotherapy (Cohort 2). Safety was assessed according to NCI CTCAE Version 4.0 and TUMAP-specific T-cell immune responses determined. Secondary observations included progression-free survival (PFS), pretreatment regulatory T cell (Treg) levels, and the effect of steroids on T-cell responses.

RESULTS

Forty-five patients were recruited. Related adverse events included minor injection site reactions, rash, pruritus, fatigue, neutropenia and single cases of allergic reaction, anemia and anaphylaxis. Two patients experienced grade 3 dose-limiting toxicity of fatigue and anaphylaxis. Of 40 evaluable patients, 36 were TUMAP responders and 20 were multi-TUMAP responders, with no important differences between cohorts. No effect of pretreatment Treg levels on IMA950 immunogenicity was observed, and steroids did not affect TUMAP responses. PFS rates were 74% at 6 months and 31% at 9 months.

CONCLUSIONS

IMA950 plus GM-CSF was well-tolerated with the primary immunogenicity endpoint of observing multi-TUMAP responses in at least 30% of patients exceeded. Further development of IMA950 is encouraged. Clin Cancer Res; 22(19); 4776-85. ©2016 AACRSee related commentary by Lowenstein and Castro, p. 4760.

Abstract 2291: On- and off target toxicity profiling for adoptive cell therapy by mass spectrometry-based immunopeptidome analysis of primary human normal tissues

A major constraint for the broad and safe application of Adoptive Cellular Therapy (ACT) is the limited number of validated tumor targets, especially for solid tumors. For T-cell receptor (TCR)-based approaches, presentation of targeted HLA-peptides on normal tissues can lead to on-target toxicity, such as severe inflammatory colitis reported upon re-directing T cells to an HLA-A*02 restricted carcinoembryonic antigen (CEA) epitope. Independently, off-target cross-reactivity of TCRs occurred in previous ACT trials, e.g. when a MAGEA3-directed TCR cross-recognized an HLA-A*01 restricted epitope from titin expressed on heart, which led to fatal cardiac toxicities. Here we present a novel approach allowing the prediction of severe on- and off-target side effects before entering into clinical trials.

We used a target discovery engine (XPRESIDENT) combining highly sensitive, quantitative mass spectrometry (LC-MS/MS), RNA-Seq-based differential transcriptomics, immunology and bioinformatics to characterize the human immunopeptidome directly on shock frozen primary human tissues. Over the last years we have built an according database for > 600 tumor samples from > 20 different tumor types and, importantly, > 300 samples from > 40 different normal tissue types, resulting in hundreds of thousands of unique HLA-peptide sequences. These data allow conclusions on which HLA peptides are actually presented on primary normal tissues in a quantitative manner, taking into account relative differences between normal tissues and tumors as well as absolute peptide copy numbers per cell. In order to assess the off-target risk for a TCR, we predict all theoretical HLA- and TCR-binding peptides in the proteome, ideally based on the binding motif of the TCR, and specifically search for actual peptide presentation by normal tissues.

When analyzing the above described CEA case, we were able to detect the CEA-derived peptide IMIGVLVGV on HLA-A*02 positive colorectal cancer samples, but importantly also on normal colorectal samples. In the original study describing the titin case tremendous experimental efforts and sophisticated cell culture models were required to retrospectively identify cross-recognition of the peptide on cardiomyocytes as the cause of toxicity. In contrast, with our approach we easily and directly identified the critical peptide ESDPIVAQY as one of the most abundantly presented peptides on an HLA-A*01 positive primary human heart sample. We show that this approach can lead to noteworthy results also for other pre-clinical and clinical stage TCR candidates.

In conclusion our data demonstrate that ultrasensitive LC-MS/MS of primary tissue may represent a fast, straightforward and meaningful complementary method to common in vitro or animal models for the prediction of on- and off-target toxicities in TCR-based immunotherapy approaches.

Citation Format: Oliver Schoor, Jens Fritsche, Sarah Kutscher, Andrea Mahr, Lea Stevermann, Annika Sonntag, Franziska Hoffgaard, Dominik Vahrenhorst, Julia Leibold, Valentina Goldfinger, Leonie Alten, Sebastian Bunk, Dominik Maurer, Steffen Walter, Hans-Georg Rammensee, Harpreet Singh-Jasuja, Toni Weinschenk. On- and off target toxicity profiling for adoptive cell therapy by mass spectrometry-based immunopeptidome analysis of primary human normal tissues. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2291.

Abstract A115: Cancer vaccine development for hepatocellular carcinoma – HEPAVAC

The HEPAVAC Consortium aims to develop a highly innovative, novel cancer vaccine approach for hepatocellular carcinoma (HCC). The international project consortium consists of 9 European Partners from academia and the biotech industry with complementary and substantial expertise in developing immunotherapeutic strategies to treat cancer. The project has started in September 2013 and is supported by the European Commission's 7th Framework Program (www.hepavac.eu).

HCC/normal adjacent tissue matched samples have been collected for HLA immunopeptidome analysis. 17 HCC samples from HLA-A*02+ patients and 15 samples from HLA-A*24+ patients have been analysed by mass spectrometry (LC-MS/MS). RNA-expression profiles have been established for 12 HCC samples. HLA-presentation/expression of peptides and mRNA on primary HCC samples are compared to n>140 normal tissue samples from relevant organs (including heart, brain, lung, kidney, liver, nerve, skin etc.) from Immatics' database.

A total of 9051 HLA-A*02-restricted different tumor-associated peptides (TUMAPs) have been identified from HLA-A*02+ samples, while a total of 3286 different HLA-A*24-restricted TUMAPs have been identified from HLA-A*24+ samples. Of these, 33 HLA-A*02+ TUMAPS and 33 HLA-A*24+ TUMAPs are currently in the process of validation, including peptide synthesis, immunogenicity testing and pharmaceutical evaluation. Most promising TUMAP candidates show selective expression only in HCC samples and no expression in normal tissues. In parallel, more than 6600 HLA-DR TUMAPs have been identified in Hep3B cells transfected with CIITA as well as an average of 1500 HLA-DR TUMAPs have been identified in HCC samples. Additional HLA-DR TUMAPs derived by distinct CIITA-transfected cell lines with different HLA-DR haplotypes are under scrutiny.

The discovery phase of the HEPAVAC project is proceeding according to the proposed timelines. HCC-specific epitopes to be included in the vaccine cocktail will be selected in the coming weeks for GMP production. In parallel, preclinical studies assessing the formulation and combination of the immunological RNA-based adjuvant (RNAdjuvant®) with peptide cocktails are underway.

Citation Format: Luigi Buonaguro, Sarah Kutscher, Roberto Accolla, Yuk T. Ma, Regina Heidenreich, Francesco Izzo, Alfred Koenigsrainer, Markus Loeffler, Phillip Mueller, Andrea Mayer, Hans-Georg Rammensee, Bruno Sangro, Sven Francque, Danila Valmori, Toni Weinschenk, Harpreet Singh-Jasuja. Cancer vaccine development for hepatocellular carcinoma – HEPAVAC. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A115.

Overnight resting of PBMC changes functional signatures of antigen specific T- cell responses: impact for immune monitoring within clinical trials

Polyfunctional CD4 or CD8 T cells are proposed to represent a correlate of immune control for persistent viruses as well as for vaccine mediated protection against infection. A well-suited methodology to study complex functional phenotypes of antiviral T cells is the combined staining of intracellular cytokines and phenotypic marker expression using polychromatic flow cytometry. In this study we analyzed the effect of an overnight resting period at 37°C on the quantity and functionality of HIV-1, EBV, CMV, HBV and HCV specific CD4 and CD8 T-cell responses in a cohort of 21 individuals. We quantified total antigen specific T cells by multimer staining and used 10-color intracellular cytokine staining (ICS) to determine IFNγ, TNFα, IL2 and MIP1β production. After an overnight resting significantly higher numbers of functionally active T cells were detectable by ICS for all tested antigen specificities, whereas the total number of antigen specific T cells determined by multimer staining remained unchanged. Overnight resting shifted the quality of T-cell responses towards polyfunctionality and increased antigen sensitivity of T cells. Our data suggest that the observed effect is mediated by T cells rather than by antigen presenting cells. We conclude that overnight resting of PBMC prior to ex vivo analysis of antiviral T-cell responses represents an efficient method to increase sensitivity of ICS-based methods and has a prominent impact on the functional phenotype of T cells.

Longitudinal changes in HIV-1-specific T-cell quality associated with viral load dynamic

BACKGROUND

Several correlates of HIV control have been described; however their predictive values remain unclear, since most studies have been performed in cross-sectional settings.

OBJECTIVES

We evaluated the cause and consequence relationship between quality of HIV-specific T-cell response and viral load dynamic in a temporal perspective.

STUDY DESIGN

HIV-1-specific T-cell responses were monitored over 7 years in a patient that following treatment interruption maintained a stable/low viral set point for 3.1 years before control of viral replication was lost and antiretroviral therapy restarted.

RESULTS

We observed that high frequencies of HIV-1-specific CD4 and CD8 T cells were unable to prevent loss of viral control. Gradual loss of functionality was observed in these responses, characterized by early loss of IL-2, viral load-dependent decrease of IFN-γ and CD154 expression as well as increase of MIP-1β production. Terminally differentiated HIV-1-specific CD8 T cells expressing CD45RA were lost independently of viral load and preceded the loss-of-control phase of HIV infection.

CONCLUSION

By describing qualitative changes in HIV-1-specific T-cell responses that coincide with loss of viral control, we identified specific correlates of disease progression and putative markers of viral control. Our findings suggest including the markers IL-2, IFN-γ, MIP-1β, CD154 and CD45RA into monitoring of HIV-specific T-cell-responses to prospectively determine correlates of protection from disease-progression.

Immune responses and association with clinical outcome of advanced colorectal cancer patients treated with the multi-peptide vaccine IMA910

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Background: IMA910 is a novel multi-peptide cancer vaccine consisting of 10 HLA class I and 3class II tumor-associated peptides (TUMAPs), which were selected based on natural presentation on colorectal tumors by the XPRESIDENT antigen discovery platform. Methods: 92 HLA-A*02+ advanced colorectal cancer (aCRC) patients (pts) with stable or responding disease after 12 weeks of first-line oxaliplatin-based therapy were enrolled in this phase I/II trial. After pre-treatment with cyclophosphamide (300 mg/m2), patients were immunized intradermally with IMA910 plus the immune modulator GM-CSF without (cohort 1; n=66) or with (cohort 2; n=26) topically applied imiquimod, another immune modulator acting via toll-like receptor 7 on antigen presenting cells. T-cell responses to individual IMA910 peptides were analyzed by HLA multimer and intracellular cytokine staining (ICS) assays. Results: IMA910 elicited immune responses towards multiple class I (43%) and class II TUMAPs (65%). 34% of pts responded to multiple class I and class II TUMAPs. Pts that received imiquimod were more often multi-peptide class I responders in the ICS assay (p=0.016) and showed an approx. 2x higher frequency of T-cell response (p=0.12). Responses to multiple class I and class II TUMAPs were associated with higher disease control rate at all time points (all p<0.02), increased time to progression (p=0.006), progression-free survival (p=0.009) and OS (p=0.088, HR=0.53). Baseline characteristics of multi vs. non-multi responders were overall well comparable. In a prospectively defined, blinded matched-pair analysis with patients in arm C of the COIN trial, multi-peptide responder patients showed a prolonged survival vs. corresponding COIN patients (p=0.04), while the non-multi responder patients had comparable survival. Conclusions: IMA910 is immunogenic. Imiquimod increases the quality of immune responses. Responses to multiple TUMAPs are associated with better clinical outcome. Several observations indicate that this association is not a reflection of better prognosis of the immunologically responding subset of patients. These results suggest further development of IMA910.

Design of therapeutic vaccines: hepatitis B as an example

Therapeutic vaccines are currently developed for chronic viral infections, such as human papillomavirus (HPV), human immunodeficiency virus (HIV), herpesvirus and hepatitis B (HBV) and C (HCV) virus infections. As an alternative to antiviral treatment or to support only partially effective therapy a therapeutic vaccine shall activate the patient's immune system to fight and finally control or ideally even eliminate the virus. Whereas the success of prophylactic vaccination is based on rapid neutralization of the invading pathogen by antibodies, virus control and elimination of infected cells require T cells. Therefore, induction of a multi-specific and multifunctional T-cell response against key viral antigens is a paradigm of therapeutic vaccination--besides activation of a humoral immune response to limit virus spread. In this review, we describe options to develop a therapeutic vaccine for chronic viral infections using HBV as a promising example.

Nef-specific CD45RA+ CD8+ T cells secreting MIP-1beta but not IFN-gamma are associated with nonprogressive HIV-1 infection

Background

Long-term survival of HIV-1 infected individuals is usually achieved by continuous administration of combination antiretroviral therapy (ART). An exception to this scenario is represented by HIV-1 infected nonprogressors (NP) which maintain relatively high circulating CD4+ T cells without clinical symptoms for several years in the absence of ART. Several lines of evidence indicate an important role of the T-cell response in the modulation of HIV-1 infection during the acute and chronic phase of the disease.

Results

We analyzed the functional and the differentiation phenotype of Nef- and Tat-specific CD8+ T cells in a cohort of HIV-1 infected NP in comparison to progressors, ART-treated seropositive individuals and individuals undergoing a single cycle of ART interruption. We observed that a distinctive feature of NP is the presence of Nef-specific CD45RA+ CD8+ T cells secreting MIP-1beta but not IFN-gamma. This population was present in 7 out of 11 NP. CD45RA+ IFN-gamma^neg MIP-1beta+ CD8+ T cells were not detected in HIV-1 infected individuals under ART or withdrawing from ART and experiencing a rebounding viral replication. In addition, we detected Nef-specific CD45RA+ IFN-gamma^neg MIP-1beta+ CD8+ T cells in only 1 out of 10 HIV-1 infected individuals with untreated progressive disease.

Conclusion

The novel antigen-specific CD45RA+ IFN-gamma^neg MIP-1beta+ CD8+ T cell population represents a new candidate marker of long-term natural control of HIV-1 disease progression and a relevant functional T-cell subset in the evaluation of the immune responses induced by candidate HIV-1 vaccines.

The intracellular detection of MIP-1beta enhances the capacity to detect IFN-gamma mediated HIV-1-specific CD8 T-cell responses in a flow cytometric setting providing a sensitive alternative to the ELISPOT

BACKGROUND

T-cell mediated immunity likely plays an important role in controlling HIV-1 infection and progression to AIDS. Several candidate vaccines against HIV-1 aim at stimulating cellular immune responses, either alone or together with the induction of neutralizing antibodies, and assays able to measure CD8 and CD4 T-cell responses need to be implemented. At present, the IFN-gamma-based ELISPOT assay is considered the gold standard and it is broadly preferred as primary assay for detection of antigen-specific T-cell responses in vaccine trials. However, in spite of its high sensitivity, the measurement of the sole IFN-gamma production provides limited information on the quality of the immune response. On the other hand, the introduction of polychromatic flow-cytometry-based assays such as the intracellular cytokine staining (ICS) strongly improved the capacity to detect several markers on a single cell level.

RESULTS

The cumulative analysis of 275 samples from 31 different HIV-1 infected individuals using an ICS staining procedure optimized by our laboratories revealed that, following antigenic stimulation, IFN-gamma producing T-cells were also producing MIP-1beta whereas T-cells characterized by the sole production of IFN-gamma were rare. Since the analysis of the combination of two functions decreases the background and the measurement of the IFN-gamma+ MIP-1beta+ T-cells was equivalent to the measurement of the total IFN-gamma+ T-cells, we adopted the IFN-gamma+ MIP-1beta+ data analysis system to evaluate IFN-gamma-based, antigen-specific T-cell responses. Comparison of our ICS assay with ELISPOT assays performed in two different experienced laboratories demonstrated that the IFN-gamma+ MIP-1beta+ data analysis system increased the sensitivity of the ICS up to levels comparable to the sensitivity of the ELISPOT assay.

CONCLUSION

The IFN-gamma+ MIP-1beta+ data evaluation system provides a clear advantage for the detection of low magnitude HIV-1-specific responses. These results are important to guide the choice for suitable highly sensitive immune assays and to build reagent panels able to accurately characterize the phenotype and function of responding T-cells. More importantly, the ICS assay can be used as primary assay to evaluate HIV-1-specific responses without losing sensitivity in comparison to the ELISPOT assay.

Chest pain after coronary interventional procedures. Incidence and pathophysiology

Chest pain following successful percutaneous coronary interventions is a common problem. Although the development of chest pain after coronary interventions may be of benign character, it is disturbing to patients, relatives and hospital staff. Such pain may be indicative of acute coronary artery closure, coronary artery spasm or myocardial infarction, but may also simply reflect local coronary artery trauma. The distinction between these causes of chest pain is crucial in selecting optimal care. Management of these patients may involve repeat coronary angiography and additional intervention. Commonly, repeat coronary angiography following percutaneous transluminal coronary angioplasty (PTCA) in patients with chest pain demonstrates widely patent lesion sites suggesting that the pain was due to coronary artery spasm, coronary arterial wall stretching or was of non-cardiac origin. As reported by the National Heart, Lung and Blood Institute PTCA Registry, 4.6% of patients after angioplasty have coronary occlusions, 4.8% suffer a myocardial infarction, and 4.2% have coronary spasm. The frequency of chest pain after new device coronary interventions (atherectomy and stenting) seems to be even higher. However, only the minority of patients with post-procedural chest pain have indeed an ischemic event. Therefore, the vast majority of patients have recurrent chest pain without any signs of ischemia. There is some evidence that non-ischemic chest pain after coronary interventions is more common after stent implantation as compared to PTCA (41% vs. 12%). This may be due to the continuous stretching of the arterial wall by the stent as the elastic recoil occurring after PTCA is minimized. In conclusion, chest pain after coronary interventional procedures may potentially be hazardous when due to myocardial ischemia. However, especially after coronary stent placement, cardiologists must consider "stretch pain" due to the overdilation and stretching of the artery caused by the stent in the differential diagnosis. Clinically, it is, therefore, important to recognize that in addition to ischemia-related chest pain other types of chest pain do exist with cardiac origin.

Nonischemic chest pain induced by coronary interventions: a prospective study comparing coronary angioplasty and stent implantation

BACKGROUND

Chest pain frequently occurs without any signs of ischemia within the first 24 hours after coronary interventions. To test the hypothesis that this pain may be due to local vessel injury ("stretch pain"), we performed a prospective study enrolling patients after PTCA, stent implantation, or diagnostic coronary angiography alone.

METHODS AND RESULTS

A total of 145 patients after coronary angiography were evaluated by a validated questionnaire for quantifying postinterventional chest pain within 24 hours. To detect myocardial ischemia, all patients were evaluated with a 12-lead ECG and cardiac isoenzymes immediately after the procedure and the morning after. After stent implantation, 21 of the 51 patients (41.2%) developed chest pain, compared with 4 of the 33 patients (12.1%) undergoing PTCA and 6 of the 61 patients (9.8%) with a diagnostic angiography (P<0.001). Of these 31 patients who developed chest pain, only 3 (9.7%) felt that the pain was similar to previously experienced angina pectoris. The minimal lumen diameter after intervention was significantly larger in the stent group than in the PTCA group (3.14+/-0.75 versus 1.95+/-0.67 mm; P<0. 001). No patient had changes in the ECG compared with before intervention, but 3 patients after stent implantation had a rise in cardiac isoenzymes. No other major adverse cardiac events occurred until discharge.

CONCLUSIONS

Nonischemic chest pain develops in almost half of all patients undergoing stent implantation and seems to be related to vessel overexpansion caused by the stent in the diseased vessel segment.