Identification of new factors associated to walking impairment in patients with vascular-type claudication.

OBJECTIVES: Mechanisms of walking limitation in arterial claudication are incompletely elucidated. We aimed to identify new variables associated to walking limitation in patients with claudication. METHODS: We retrospectively analyzed data of 1120 patients referred for transcutaneous exercise oxygen pressure recordings (TcpO2). The outcome measurement was the absolute walking time on treadmill (3.2 km/h, 10% slope). We used both: linear regression analysis and a non-linear analysis, combining support vector machines and genetic explanatory in 800 patients with the following resting variables: age, gender, body mass index, the presence of diabetes, minimal ankle to brachial index at rest, usual walking speed over 10 m (usual-pace), number of comorbid conditions, active smoking, resting heart rate, pre-test glycaemia and hemoglobin, beta-blocker use, and exercise-derived variables: minimal value of pulse oximetry, resting chest-TcpO2, decrease in chest TcpO2 during exercise, presence of buttock ischemia defined as a decrease from rest of oxygen pressure index ≤15 mmHg. We tested the models over 320 other patients. RESULTS: Independent variables associated to walking time, by decreasing importance in the models, were: age, ankle to brachial index, usual-pace; resting TcpO2, body mass index, smoking, buttock ischemia, heart rate and beta-blockers for the linear regression analysis, and were ankle to brachial index, age, body mass index, usual-pace, decrease in chest TcpO2, smoking, buttock ischemia, glycaemia, heart rate for the non-linear analysis. Testing of models over 320 new patients gave r = 0.509 for linear and 0.575 for non-linear analysis (both p < 0.05). CONCLUSION: Buttock ischemia, heart rate and usual-pace are new variables associated to walking time.

Long-term prognostic significance of right bundle-branch morphology ventricular ectopy induced during stress test in patients with intermediate to high probability of coronary artery disease.

Aims: Stress-induced right bundle-branch block morphology ventricular ectopy (SI-RBVE) may be caused by left ventricular myocardial anomalies. While frequent ventricular ectopy (FVE) has been linked to poor outcomes, the prognostic value of SI-RBVE has not been established. The study aims to determine whether SI-RBVE is associated with increased mortality. Methods and results: Three hundred forty-three patients with an intermediate to high probability of coronary artery disease were prospectively included. Patients were referred for a single-photon emission computed tomography and underwent a stress test according to standard protocols. Stress-induced right bundle-branch block morphology ventricular ectopy (VE) was defined as one or more induced premature beats with positive predominance in V1. Frequent VE was defined as the presence of seven or more ventricular premature beats per minute or any organized ventricular arrhythmia. During a mean follow-up of 4.5 ± 1.3 years, 59 deaths occurred. The death rate was higher in the SI-RBVE group (23.4% vs. 14.0%, P = 0.021). Age [odds ratio (OR) = 1.09 (95% CI: 1.06-1.13), P < 0.001] and peripheral artery disease [OR = 2.47 (95% CI: 1.35-4.50) P = 0.003] were independent factors of mortality, but single-photon emission computed tomography findings were not. There was an interaction between SI-RBVE and left ventricular ejection fraction (LVEF). In patients with LVEF > 50%, SI-RBVE was an incremental risk factor for mortality [OR = 2.83 (95% CI: 1.40-5.74), P = 0.004]. Stress-induced right bundle-branch block morphology VE patients also presented higher rates of known coronary artery disease, ischaemia, scar, and ST-segment changes. Frequent VE was not related to mortality. Conclusion: Stress-induced right bundle-branch block morphology VE is associated with an increased mortality in patients with preserved LVEF.

Evaluation of HEAR score to rule-out major adverse cardiac events without troponin test in patients presenting to the emergency department with chest pain.

BACKGROUND AND IMPORTANCE: Current guidelines for patients presenting to the emergency department with chest pain without ST-segment elevation myocardial infarction (non-STEMI) on electrocardiogram are based on troponin measurement. The HEART score is reportedly a reliable work-up strategy that combines clinical evaluation with troponin value. A clinical rule that could select very low-risk patients without the need for a blood test (HEAR score, being the HEART score without the troponin item) would be of great interest. OBJECTIVES: To prospectively assess the safety of a HEAR score <2 to rule-out non-STEMI without troponin measurement. Secondary objective was to assess the safety of a sequential strategy that combines HEAR score and HEART (defined as two-step HEART strategy). DESIGN, SETTINGS AND PARTICIPANTS: Prospective observational study in six emergency departments. Patients with nontraumatic chest pain and no alternative diagnosis were included and followed up for 45 day. Patients were considered at low-risk if the HEAR score was <2 or, for the two-step HEART strategy, if the HEART score was <4. OUTCOMES MEASURE AND ANALYSIS: The primary endpoint was the 45-day rate of major adverse cardiac events (MACE) in patients with a HEAR score <2. A HEAR score based strategy was consider safe if the rate of the primary endpoint was below 1%, with an upper margin of the 95% confidence interval (CI) below 3%. RESULTS: Among 1452 patients included, 1402 were analyzed and 97 (7%) had a MACE during the follow-up period. The HEAR score was <2 in 279 (20%) patients and one presented a MACE [0.4% (95% CI: 0.01-1.98)]. The two-step HEART strategy classified low-risk an additional 476 patients (34%) and one of these 476 patients had a MACE [0.3% (95% CI: 0.03-0.95)]. The two-step HEART strategy would have theoretically avoided 360 troponin measurements (19%). CONCLUSIONS: In our prospective multicenter study, a HEAR based work-up strategy was safe, with a very low risk of MACE at 45 day. We also report that a two-step HEART-based strategy may safely allow significant reduction of troponin measurements in patients presenting to the emergency department with chest pain.