Safety profile and utility of treadmill exercise in patients with high-gradient hypertrophic cardiomyopathy.

BACKGROUND: Exercise echocardiography in the evaluation of hypertrophic cardiomyopathy (HCM) provides valuable information for risk stratification, selection of optimal treatment, and prognostication. However, HCM patients with left ventricular outflow tract gradients ≥30mm Hg are often excluded from exercise testing because of safety considerations. We examined the safety and utility of exercise testing in patients with high-gradient HCM. METHODS: We evaluated clinical characteristics, hemodynamics, and imaging variables in 499 consecutive patients with HCM who performed 959 exercise tests. Patients were divided based on peak left ventricular outflow tract gradients using a 30-mm Hg threshold into the following: obstructive (n=152), labile-obstructive (n=178), and nonobstructive (n=169) groups. RESULTS: There were no deaths during exercise testing. We noted 20 complications (2.1% of tests) including 3 serious ventricular arrhythmias (0.3% of tests). There was no difference in complication rate between groups. Patients with obstructive HCM had a higher frequency of abnormal blood pressure response (obstructive: 53% vs labile: obstructive: 41% and nonobstructive: 37%; P=.008). Obstructive patients also displayed a lower work capacity (obstructive: 8.4±3.4 vs labile obstructive: 10.9±4.2 and nonobstructive: 10.2±4.0, metabolic equivalent; P<.001). Exercise testing provided incremental information regarding sudden cardiac death risk in 19% of patients with high-gradient HCM, and we found a poor correlation between patient-reported functional class and work capacity. CONCLUSION: Our results suggest that exercise testing in HCM is safe, and serious adverse events are rare. Although numbers are limited, exercise testing in high-gradient HCM appears to confer no significant additional safety hazard in our selected cohort and could potentially provide valuable information.

Percutaneous coronary intervention without onsite cardiac surgery.

INTRODUCTION: Danish health authorities have major concerns with regard to the risk and the quality of care of percutaneous coronary intervention (PCI) without onsite cardiac surgery. We report the results of the first Danish PCI centre without onsite cardiac surgery. MATERIAL AND METHODS: A total of 245 patients underwent 254 elective PCIs during a six-month study period. The outcome measures were treatment latency, health care costs, mortality rate, major adverse cardiovascular events, symptom relief and quality-of-life at six-month follow-up. RESULTS: The median treatment latency was reduced from 28 to no days (p < 0.05) for patients with stable disease, and from seven to no days (p < 0.05) for patients with unstable disease. Health care costs were reduced by 4,246,652 DKK. The six-month mortality was 0.0% versus a predicted 0.4% New York State PCI-score in patients with stable disease, and a 1.4% observed study score versus a predicted 6.4% GRACE-score in patients with unstable disease. No patients required emergency bypass surgery. At six months, five myocardial infarctions (two periprocedural and two subacute stent thromboses), three restenoses and no in-stent restenosis had occurred, while angina was absent or reduced in 92% and quality-of-life had improved in 73% of the patients. CONCLUSION: Local PCI without onsite cardiac surgery was safe, quality of care was increased, health care costs were reduced and patient-perceived treatment effect was excellent.