Impacto del cateterismo derecho de ejercicio en el diagnóstico diferencial de la enfermedad tromboembólica pulmonar crónica / Value of exercise right heart catheterization in the differential diagnosis of chronic thromboembolic pulmonary disease

Introduction and objectives Chronic thromboembolic disease refers to the presence of chronic thrombotic pulmonary vascular thrombosis without pulmonary hypertension (PH) at rest but with exercise limitation after pulmonary embolism (PE). Our aim was to evaluate the hemodynamic response to exercise in these patients and its correlation with the values reached in cardiopulmonary exercise testing. Methods We included symptomatic patients with persistent pulmonary thrombosis after PE. We excluded patients with left heart disease or significant PH (mean pulmonary arterial pressure [mPAP] >25mmHg, pulmonary vascular resistance >3 WU, and pulmonary capillary wedge pressure [PCWP] >15mmHg). Cardiopulmonary exercise testing and exercise right heart catheterization were performed. Exercise-induced precapillary PH was defined as mPAP/CO slope >3 and PCWP/CO slope <2mmHg/l/min. The hemodynamic response and the values obtained in cardiopulmonary exercise testing were compared between patients with and without exercise-induced precapillary PH. Results We studied 36 patients; 4 were excluded due to incomplete hemodynamic data. Out of the 32 patients analyzed; 3 developed a pathological increase in PCWP. Among the remaining 29 patients (mean age, 49.4±13.7 years, 34.5% women), 13 showed exercise-induced PH. Resting mPAP was higher in those who developed exercise-induced PH (23.3±5.4 vs 19.0±3.8mmHg; P=.012), although CO was similar in the 2 groups. Patients with exercise-induced PH exhibited data of ventilatory inefficiency with reduced values of end-tidal CO2 pressure at the anaerobic threshold (32.8±3.0 vs 36.2±3.3mmHg; P=.021) and a higher Ve/VCO2 slope (34.2±4.8 vs 30.7±5.0; P=.049). Conclusions Exercise limitation and ventilatory inefficiency could be attributable to exercise-induced precapillary PH in a subgroup of patients with persistent pulmonary thrombosis and dyspnea (AU)

Introdución y objetivos La enfermedad tromboembólica crónica se define como la trombosis crónica de la vasculatura pulmonar y disnea, sin hipertensión pulmonar (HP) en reposo tras una embolia de pulmón. El estudio evaluó la hemodinámica al esfuerzo en estos pacientes y su relación con la ergoespirometría. Métodos Se incluyó a pacientes sintomáticos con trombosis pulmonar crónica tras una embolia de pulmón. Se excluyó a los pacientes con cardiopatía izquierda o HP significativa en reposo (presión arterial pulmonar media [PAPm] >25mmHg, resistencia vascular pulmonar >3 UW y presión capilar pulmonar [PCP] >15mmHg). Se realizó una ergoespirometría y un cateterismo derecho de ejercicio. La HP precapilar al ejercicio se definió como las pendientes PAPm/gasto cardiaco >3 y PCP/gasto cardiaco <2mmHg/l/min. Se comparó la respuesta hemodinámica y ergoespirométrica entre pacientes con y sin HP precapilar al ejercicio. Resultados Se estudió a 36 pacientes, excluyéndose 4 por calidad subóptima en el registro hemodinámico. Tres pacientes presentaron una elevación patológica de la PCP. De los 29 restantes (edad, 49,4±13,7 años; el 34,5% mujeres), en 13 se halló HP precapilar al ejercicio. La PAPm basal fue mayor en aquellos con HP al ejercicio (23,3±5,4 frente a 19,0±3,8mmHg; p=0,012), con similar gasto cardiaco. Aquellos con HP al ejercicio exhibieron valores reducidos de la presión de CO2 exahalada en el umbral anaeróbico (32,8±3,0 frente a 36,2±3,3mmHg; p=0,021) y mayor pendiente Ve/VCO2 (34,2±4,8 frente a 30,7±5,0; p=0,049). Conclusiones La HP precapilar al ejercicio se asocia con limitación funcional e ineficiencia ventilatoria en un subgrupo de pacientes con trombosis arterial pulmonar crónica y disnea persistente (AU)

Catheter-directed therapy for acute pulmonary embolism: results of a multicenter national registry.

INTRODUCTION AND OBJECTIVES: Catheter-directed therapy (CDT) for acute pulmonary embolism (PE) is an emerging therapy that combines heterogeneous techniques. The aim of the study was to provide a nationwide contemporary snapshot of clinical practice and CDT-related outcomes. METHODS: This Investigator-initiated multicenter registry aimed to include consecutive patients with intermediate-high risk (IHR) or high-risk (HR), acute PE eligible for CDT. The primary outcome of the study was in-hospital all-cause death. RESULTS: A total of 253 patients were included, of whom 93 (36.8%) had HR-PE, and 160 (63.2%) had IHR-PE with a mean age of 62.3±15.1 years. Local thrombolysis was performed in 70.8% and aspiration thrombectomy in 51.8%, with 23.3% of patients receiving both. However, aspiration thrombectomy was favored in the HR-PE cohort (80.6% vs 35%; P<.001). Only 51 patients (20.2%) underwent CDT with specific PE devices. The success rate for CDT was 90.9% (98.1% of IHR-PE patients vs 78.5% of HR-PE patients, P<.001). In-hospital mortality was 15.5%, and was highly concentrated in the HR-PE patients (37.6%) and significantly lower in IHR-PE patients (2.5%), P<.001. Long-term (24-month) mortality was 40.2% in HR-PE patients vs 8.2% in IHR-PE patients (P<.001). CONCLUSIONS: Despite the high success rate for CDT, in-hospital mortality in HR-PE is still high (37.6%) compared with very low IHR-PE mortality (2.5%).

Value of exercise right heart catheterization in the differential diagnosis of chronic thromboembolic pulmonary disease.

INTRODUCTION AND OBJECTIVES: Chronic thromboembolic disease refers to the presence of chronic thrombotic pulmonary vascular thrombosis without pulmonary hypertension (PH) at rest but with exercise limitation after pulmonary embolism (PE). Our aim was to evaluate the hemodynamic response to exercise in these patients and its correlation with the values reached in cardiopulmonary exercise testing. METHODS: We included symptomatic patients with persistent pulmonary thrombosis after PE. We excluded patients with left heart disease or significant PH (mean pulmonary arterial pressure [mPAP] >25mmHg, pulmonary vascular resistance >3 WU, and pulmonary capillary wedge pressure [PCWP] >15mmHg). Cardiopulmonary exercise testing and exercise right heart catheterization were performed. Exercise-induced precapillary PH was defined as mPAP/CO slope >3 and PCWP/CO slope <2mmHg/l/min. The hemodynamic response and the values obtained in cardiopulmonary exercise testing were compared between patients with and without exercise-induced precapillary PH. RESULTS: We studied 36 patients; 4 were excluded due to incomplete hemodynamic data. Out of the 32 patients analyzed; 3 developed a pathological increase in PCWP. Among the remaining 29 patients (mean age, 49.4±13.7 years, 34.5% women), 13 showed exercise-induced PH. Resting mPAP was higher in those who developed exercise-induced PH (23.3±5.4 vs 19.0±3.8mmHg; P=.012), although CO was similar in the 2 groups. Patients with exercise-induced PH exhibited data of ventilatory inefficiency with reduced values of end-tidal CO2 pressure at the anaerobic threshold (32.8±3.0 vs 36.2±3.3mmHg; P=.021) and a higher Ve/VCO2 slope (34.2±4.8 vs 30.7±5.0; P=.049). CONCLUSIONS: Exercise limitation and ventilatory inefficiency could be attributable to exercise-induced precapillary PH in a subgroup of patients with persistent pulmonary thrombosis and dyspnea.

Bleeding in Patients Undergoing Transfemoral Transcatheter Aortic Valve Replacement: Incidence, Trends, Clinical Outcomes, and Predictors.

BACKGROUND: Bleeding is one of the most frequent complications in patients undergoing transcatheter aortic valve replacement (TAVR). Importantly, major bleeding is associated with poor clinical outcomes after TAVR. However, large studies on bleeding complications in the contemporary TAVR population are limited. OBJECTIVES: The aim of this study was to assess the incidence, temporal trends, clinical outcomes, and predictors of bleeding in patients undergoing transfemoral TAVR. METHODS: The CENTER2 study is a pooled patient-level database from 10 clinical studies including patients who underwent TAVR between 2007 and 2022. RESULTS: A total of 23,562 patients underwent transfemoral TAVR. The mean age was 81.5 ± 6.7 years, and 56% were women. Major bleeding within the first 30 days was observed in 1,545 patients (6.6%). Minor bleeding was reported in 1,143 patients (4.7%). Rates of major bleeding decreased from 11.5% in 2007-2010 to 5.5% in 2019-2022 (Ptrend < 0.001). Dual antiplatelet therapy was associated with higher major bleeding rates compared with single antiplatelet therapy (12.2% vs 9.1%; OR: 1.40; 95% CI: 1.13-1.72; P = 0.002). Patients with major bleeding had increased mortality risk during the first 30 days (14.1% vs 4.3%; OR: 3.66; 95% CI: 3.11-4.31; P < 0.001) and during 1-year follow-up (27.8% vs 14.5%; HR: 1.50; 95% CI: 1.41-1.59; P < 0.001). Minor bleeding did not affect 1-year mortality risk (16.7% vs 14.5%; HR: 1.11; 95% CI: 0.93-1.32; P = 0.27). Predictors of major bleeding were female sex and peripheral vascular disease. CONCLUSIONS: Bleeding complications remain frequent and important in patients undergoing transfemoral TAVR. Increased mortality risk in major bleeding persists after the initial 30 days. (Cerebrovascular Events in Patients Undergoing Transcatheter Aortic Valve Implantation With Balloon-Expandable Valves Versus Self-Expandable Valves [CENTER]; NCT03588247).

Initial results of investigator initiated international database on catheter directed therapy of acute pulmonary embolism.

BACKGROUND: Catheter directed therapies (CDT) are widely used in the treatment of acute pulmonary embolism (PE). A multicenter registry was organized to evaluate their application in real life and to determine efficacy and safety of these procedures. Local experience of participating centers in percutaneous techniques for PE treatment was assessed. METHODS: An internet-based registry was designed to collect clinical, echocardiographic and laboratory data of consecutive PE patients treated with CDT in participating centers between 2017 and 2022. RESULTS: Under analysis were 145 consecutive patients with acute PE, aged 61 ± 15 years, treated with CDT in 7 centers: 50 (34.5%) patients with high-risk PE (HRPE), and 95 (65.5%) patients with intermediate-high risk PE (IHRPE). 100 (69%) patients were treated with dedicated devices, in 45 (31%) subjects a pigtail catheter was used. Total PE or CDT related in-hospital mortality in HRPE reached 14% (7 patients), while in IHRPE 3.2% (3 patients) (p = 0.032). 50% of PE or CDT related deaths occurred in patients treated with a pigtail catheter. All-cause mortality in 145 patients was 9.7%, and it was higher in HRPE than in IHRPE (18% vs. 5.3%, p = 0.019). The use of pigtail catheters compared to dedicated systems was associated with higher mortality (20% vs. 5%, p = 0.01). CONCLUSIONS: Catheter directed therapies is a real option of treating PE. It was used as primary therapy also in patients without contraindication for thrombolysis suggesting that clinical practice does not always follow current PE guidelines. Patients treated with dedicated CDT systems had a higher survival rate than subjects treated with pigtail catheters.

Effectiveness and Safety of Balloon Pulmonary Angioplasty for the Treatment of Patients with Persistent Pulmonary Hypertension after Pulmonary Endarterectomy.

(1) Background: Pulmonary endarterectomy (PEA) is the "gold standard" treatment for operable patients with chronic thromboembolic pulmonary hypertension (CTEPH). Persistent pulmonary hypertension (PH) after PEA confers a worse prognosis. Balloon pulmonary angioplasty (BPA) could represent a useful therapy in this setting, but evidence about its effectiveness and safety in patients with previous PEA is limited. (2) Methods: A total of 14 patients with persistent PH after PEA were treated with BPA in a single PH center. Hemodynamic and clinical effects of BPA and complications of the procedure were retrospectively collected. (3) Results: After BPA, the mean pulmonary arterial pressure fell from 50.7 ± 15.3 mmHg to 38.0 ± 7.9 mmHg (25.0% decrease; 95% confidence interval (CI) 14.0-35.5%; p = 0.01). Pulmonary vascular resistances were reduced from 8.5 ± 3.6 WU to 5.3 ± 2.2 WU (37.6% decrease; 95% CI 18.8-56.5%; p = 0.01). WHO functional class was also improved with BPA. Severe BPA-related complications were infrequent and no periprocedural deaths were observed. (4) Conclusions: BPA is an effective and safe therapy for patients with CTEPH and persistent PH after PEA.

Balloon pulmonary angioplasty can be an effective and safe therapeutic option in non-surgical elderly patients.

Background: Advanced age, frailty, and age-related comorbidities are the major causes of pulmonary endarterectomy disqualification in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Balloon pulmonary angioplasty (BPA) is an attractive and less invasive therapy for elderly patients. However, information about the safety, procedure tolerance, and effectiveness of BPA in elderly patients is limited. Objective and methods: We aimed to analyze the safety, tolerance, and efficacy of BPA in CTEPH patients aged ≥70 years. This observational, descriptive, and retrospective series included consecutive patients aged ≥70 years, who underwent completed or interrupted BPA programs at a pulmonary hypertension reference center between May 2013 and May 2022. Results: We enrolled 155 patients in our institution's BPA program. Among these, 33 patients were aged ≥70 years (mean age, 76.4 years; women, 75.8%) and had finished or interrupted BPA programs. In this cohort, we performed 116 BPA procedures (average, 3.6 ± 1.8 sessions/patient). Among the 33 patients, 19 (57.6%) completed treatment for all lobes, while the BPA program was interrupted in the remaining 14 (42.4%). Among all 33 patients, BPA was associated with a significant reduction in mean pulmonary arterial pressure (39.2 ± 9.3 vs. 32.8 ± 8.8 mmHg; p < 0.001) and pulmonary vascular resistance (6.7 ± 3.1 vs. 4.4 ± 2.0 WU; p < 0.001), along with an improvement in the cardiac index (2.5 ± 0.6 vs. 2.8 ± 0.7 L/min/m2; p = 0.04) with significant reductions in the N-terminal prohormone of brain natriuretic peptide level (pre-BPA, 353 pg/mL [207-1,960 pg/mL] vs. post-BPA, 167 pg/mL [73-629 pg/mL]; p = 0.03). The patients' functional class improved, and pulmonary hypertension-targeting drug requirements were significantly reduced. The pulmonary injury appeared in 3.4% of the 116 procedures, of which 50% were of grade 2. No patient of ≥70 years had grade 5 pulmonary injury. One periprocedural mortality was recorded (3%), and the median follow-up period was 2.8 years. The survival rate of the entire cohort at 1 and 3 years was 90.5 and 82.8%, respectively. Conclusion: BPA is an effective and safe approach in patients aged ≥70 years. It significantly improves patients' functional class, hemodynamic, and biomarkers, and reduces their pulmonary hypertension-targeting medical therapy requirements. These successes were achieved even though a significant percentage of patients did not complete the therapy. The rates of procedural complications and periprocedural mortality were low. Survival at 1 and 3 years was good in comparison to that of younger patients undergoing BPA.

Coronary Compression Following Percutaneous Pulmonary Valve Implantation Despite a Negative Balloon Sizing Test: Lessons Learnt From This Unusual Complication.

A 16-years-old male with prior diagnosis of situs inversus totalis and pulmonary atresia with interventricular communication underwent percutaneous pulmonary valve implantation 3 months after successful RVOT stenting following a negative balloon sizing test. Once finished the procedure, after consciousness recovery in the intensive care unit, the patient developed oppressive chest pain with very subtle electrocardiographic changes over his basal right bundle branch block. An urgent coronary angiography showed a severe stenosis in the proximal right coronary artery with TIMI 2 distal flow. Intravascular ultrasound imaging confirmed extrinsic compression. A 4 × 21 mm drug-eluting stent was successfully implanted relieving symptoms immediately. TIMI 3 flow was restored and good apposition and expansion were confirmed with intravascular ultrasound. A carefully review of the procedure showed that the pitfall responsible for this complication was the oversizing of the valve with respect to the size of the balloon used for the sizing test.

Factores de riesgo de muerte hospitalaria en pacientes con infarto agudo de miocardio durante la pandemia de la COVID-19 / Risk factors for in-hospital mortality in patients with acute myocardial infarction during the COVID-19 outbreak

INTRODUCCIÓN Y OBJETIVOS: A pesar de los avances en el tratamiento del infarto agudo de miocardio (IAM), este sigue presentando un pronóstico desfavorable. Hay poca evidencia acerca de la evolución de los pacientes con IAM y la enfermedad coronavírica de 2019 (COVID-19). El objetivo del estudio es describir la presentación clínica, las complicaciones y los factores predictores de mortalidad hospitalaria en pacientes con IAM durante el brote de COVID-19 en España. MÉTODOS: Se realizó un estudio de cohortes, prospectivo y multicéntrico de todos los pacientes consecutivos con IAM en tratamiento invasivo durante el brote de COVID19 (15 de marzo a 15 de abril de 2020). Se compararon las características clínicas de los pacientes positivos para COVID-19 con las de los negativos, y se evaluó el efecto de la COVID-19 en la mortalidad mediante emparejamiento por puntuación de propensión y regresión logística. RESULTADOS: Se incluyó a 187 pacientes con IAM: 111 con elevación del segmento ST y 76 sin elevación. De ellos, 32 (17%) resultaron positivos para COVID-19. Las puntuaciones GRACE y Killip-Kimball y varios marcadores inflamatorios resultaron significativamente mayores en los pacientes con COVID-19. La mortalidad total y cardiovascular fueron significativamente mayores en los pacientes con COVID-19 (el 25 frente al 3,8%; p < 0,001; y el 15,2 frente al 1,8%; p = 0,001). La puntuación GRACE > 140 (OR = 23,45; IC95%, 2,52-62,51; p = 0,005) y la COVID-19 (OR = 6,61; IC95%, 1,82-24,43; p = 0,02) resultaron factores independientes de mortalidad hospitalaria. CONCLUSIONES: Durante el brote epidémico, la puntuación GRACE elevada y la COVID19 fueron los factores independientes de mortalidad hospitalaria en los pacientes con IAM

INTRODUCTION AND OBJECTIVES: Despite advances in treatment, patients with acute myocardial infarction (AMI) still exhibit unfavorable short- and long-term prognoses. In addition, there is scant evidence about the clinical outcomes of patients with AMI and coronavirus disease 2019 (COVID-19). The objective of this study was to describe the clinical presentation, complications, and risk factors for mortality in patients admitted for AMI during the COVID-19 pandemic. METHODS: This prospective, multicenter, cohort study included all consecutive patients with AMI who underwent coronary angiography in a 30-day period corresponding chronologically with the COVID-19 outbreak (March 15 to April 15, 2020). Clinical presentations and outcomes were compared between COVID-19 and non-COVID-19 patients. The effect of COVID-19 on mortality was assessed by propensity score matching and with a multivariate logistic regression model. RESULTS: In total, 187 patients were admitted for AMI, 111 with ST-segment elevation AMI and 76 with non-ST-segment elevation AMI. Of these, 32 (17%) were diagnosed with COVID-19. GRACE score, Killip-Kimball classification, and several inflammatory markers were significantly higher in COVID-19-positive patients. Total and cardiovascular mortality were also significantly higher in COVID-19-positive patients (25% vs 3.8% [P < .001] and 15.2% vs 1.8% [P = .001], respectively). GRACE score > 140 (OR, 23.45; 95%CI, 2.52-62.51; P = .005) and COVID-19 (OR, 6.61; 95%CI, 1.82-24.43; P = .02) were independent predictors of in-hospital death. CONCLUSIONS: During this pandemic, a high GRACE score and COVID-19 were independent risk factors associated with higher in-hospital mortality

[Risk factors for in-hospital mortality in patients with acute myocardial infarction during the COVID-19 outbreak]. / Factores de riesgo de muerte hospitalaria en pacientes con infarto agudo de miocardio durante la pandemia de la COVID-19.

INTRODUCTION AND OBJECTIVES: Despite advances in treatment, patients with acute myocardial infarction (AMI) still exhibit unfavorable short- and long-term prognoses. In addition, there is scant evidence about the clinical outcomes of patients with AMI and coronavirus disease 2019 (COVID-19). The objective of this study was to describe the clinical presentation, complications, and risk factors for mortality in patients admitted for AMI during the COVID-19 pandemic. METHODS: This prospective, multicenter, cohort study included all consecutive patients with AMI who underwent coronary angiography in a 30-day period corresponding chronologically with the COVID-19 outbreak (March 15 to April 15, 2020). Clinical presentations and outcomes were compared between COVID-19 and non-COVID-19 patients. The effect of COVID-19 on mortality was assessed by propensity score matching and with a multivariate logistic regression model. RESULTS: In total, 187 patients were admitted for AMI, 111 with ST-segment elevation AMI and 76 with non-ST-segment elevation AMI. Of these, 32 (17%) were diagnosed with COVID-19. GRACE score, Killip-Kimball classification, and several inflammatory markers were significantly higher in COVID-19-positive patients. Total and cardiovascular mortality were also significantly higher in COVID-19-positive patients (25% vs 3.8% [P < .001] and 15.2% vs 1.8% [P = .001], respectively). GRACE score > 140 (OR, 23.45; 95%CI, 2.52-62.51; P = .005) and COVID-19 (OR, 6.61; 95%CI, 1.82-24.43; P = .02) were independent predictors of in-hospital death. CONCLUSIONS: During this pandemic, a high GRACE score and COVID-19 were independent risk factors associated with higher in-hospital mortality.Full English text available from:www.revespcardiol.org/en.

Risk factors for in-hospital mortality in patients with acute myocardial infarction during the COVID-19 outbreak.

INTRODUCTION AND OBJECTIVES: Despite advances in treatment, patients with acute myocardial infarction (AMI) still exhibit unfavorable short- and long-term prognoses. In addition, there is scant evidence about the clinical outcomes of patients with AMI and coronavirus disease 2019 (COVID-19). The objective of this study was to describe the clinical presentation, complications, and risk factors for mortality in patients admitted for AMI during the COVID-19 pandemic. METHODS: This prospective, multicenter, cohort study included all consecutive patients with AMI who underwent coronary angiography in a 30-day period corresponding chronologically with the COVID-19 outbreak (March 15 to April 15, 2020). Clinical presentations and outcomes were compared between COVID-19 and non-COVID-19 patients. The effect of COVID-19 on mortality was assessed by propensity score matching and with a multivariate logistic regression model. RESULTS: In total, 187 patients were admitted for AMI, 111 with ST-segment elevation AMI and 76 with non-ST-segment elevation AMI. Of these, 32 (17%) were diagnosed with COVID-19. GRACE score, Killip-Kimball classification, and several inflammatory markers were significantly higher in COVID-19-positive patients. Total and cardiovascular mortality were also significantly higher in COVID-19-positive patients (25% vs 3.8% [P <.001] and 15.2% vs 1.8% [P=.001], respectively). GRACE score> 140 (OR, 23.45; 95%CI, 2.52-62.51; P=.005) and COVID-19 (OR, 6.61; 95%CI, 1.82-24.43; P=.02) were independent predictors of in-hospital death. CONCLUSIONS: During this pandemic, a high GRACE score and COVID-19 were independent risk factors associated with higher in-hospital mortality.

Tratamiento de la obstrucción del tracto de salida en la miocardiopatía hipertrófica mediante reparación mitral: «miectomía sin miectomía» / Mitral repair as a treatment of outflow tract obstruction in hypertrophic cardiomyopathy: "myectomy without myectomy"

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A clinical score to obviate the need for cardiac stress testing in patients with acute chest pain and negative troponins.

INTRODUCTION: Although cardiac stress testing may help establish the safety of early discharge in patients with suspected acute coronary syndromes and negative troponins, more cost-effective strategies are necessary. We aimed to develop a clinical prediction rule to safely obviate the need for cardiac stress testing in this setting. METHODS: A decision rule was derived in a prospective cohort of 3001 patients with acute chest pain and negative troponins, and validated in a set of 1473 subjects. The primary end point was a composite of positive cardiac stress testing (in the absence of a subsequent negative coronary angiogram), positive coronary angiography, or any major coronary events within 3 months. RESULTS: A score chart was built based on 7 variables: male sex (+2), age (+1 per decade from the fifth decade), diabetes mellitus (+2), hypercholesterolemia (+1), prior coronary revascularization (+2), type of chest pain (typical angina, +5; non-specific chest pain, -3), and non-diagnostic repolarization abnormalities (+2). In the validation set, the model showed good discrimination (c statistic = 0.84; 95% confidence interval, 0.82-0.87) and calibration (Hosmer-Lemeshow goodness-of-fit test, P= .34). If stress tests were avoided in patients in the validation sample with a sum score of 0 or lower, the number of referrals would be reduced by 23.4%, yielding a negative predictive value of 98.8% (95% confidence interval, 97.0%-99.7%). CONCLUSION: This novel prediction rule based on a combination of readily available clinical characteristics may be a valuable tool to decide whether stress testing can be reliably avoided in patients with acute chest pain and negative troponins.