Zbigniew Bednarkiewicz

Myocardial ischemia and autonomic activity in dippers and non-dippers with coronary artery disease: assessment of normotensive and hypertensive patients.

OBJECTIVES The aim of this study was to assess the relations between the circadian variations of blood pressure (BP) and the pattern of ischemia and autonomic activity in normotensive and hypertensive patients with coronary artery disease (CAD). PATIENTS AND METHODS On the basis of the results of ambulatory BP monitoring, 115 patients with stable CAD were divided into Group 1 (with arterial hypertension) and Group 2 (normotensives). Groups were subdivided into dippers and non-dippers. Holter monitoring was performed to assess the occurrence and circadian pattern of ischemic episodes. Time domain and frequency domain HRV analyses were performed to evaluate the autonomic activity. RESULTS The total number of ischemic episodes was similar in dippers and non-dippers. Non-dippers had a greater number of silent episodes and a different circadian pattern of ischemia with more night episodes. Among the time-domain HRV parameters, only SDNN was similar in dippers and non-dippers. Non-dippers had lower pNN50 and rMSSD-the parameters expressing parasympathetic activity. Differences between diurnal and nocturnal results of spectral HRV analysis were observed in dipper patients only. They presented an elevation of HF power and a decline of LF power at night. All differences between dippers and non-dippers were of similar significance in both hypertensives and normotensives. CONCLUSIONS A lack of a nocturnal fall in BP is present in normotensive and hypertensive patients with CAD. Non-dippers with CAD had silent and nighttime ischemia more often. They also had an abnormal pattern of autonomic activity with higher sympathetic and lower parasympathetic modulation.

Predictors of successful acetylsalicylic acid resistance suppression after percutaneous coronary revascularisation

BACKGROUND AND AIM There is no established management of resistance to acetylsalicylic acid (ASA) in patients with coronary artery disease (CAD). We hypothesised that simply doubling the usual daily dose of ASA could be effective in overcoming ASA resistance. METHODS Our study comprised 40 subjects with CAD (male 67.5%, mean age 60.5 ± 8.8 years, mean body mass index 26.9 ± 2.7 kg/m² and median aspirin reaction unit [ARU] value obtained with a Verify Now Aspirin Test 612 [573-634]) with resistance to 75 mg/daily ASA defined as ARU ≥ 550. According to the overcoming of resistance or lack there of in a repeated test after four weeks of 150 mg daily ASA treatment, we defined two subsets: subjects who regained ASA sensitivity, and those who did not. RESULTS Successful overcoming of ASA resistance was observed in 62.5% of patients. Multivariate analysis regression confirmed that two variables independently determined successful ASA resistance suppression: male gender (OR 6.88; 95% CI 1.29-36.75; p = 0.024), and ARU for 75 mg daily (OR 0.97 per unit at 75 mg; 95% CI 0.94-0.99; p = 0.039). ROC analysis indicated that the threshold value at which ARU at 75 mg ASA treatment was predictive of successful ASA resistance overcoming was ≤ 608 ARU. Using a simple point score (one point for male gender and one for initial ARU ≤ 608), we found that ASA resistance was overcome in 8%, 36% and 56% of patients, when zero, any single, or two predictors were present. CONCLUSIONS ASA resistance overcoming by dose doubling can be achieved more often in males and in subjects with lower ARU value at ASA 75 mg.