Use and efficacy of saline hydration and N-acetyl cysteine to prevent contrast-induced nephropathy in low-risk populations undergoing coronary artery angiography.

Contrast-induced nephropathy (CIN) is most commonly defined as acute renal failure occurring within 48-72 h of exposure to an intravascular radiographic contrast medium that is not attributable to other causes. In the international literature, a 25% increase in serum creatinine levels or an increase in absolute values of 0.5 mg/dl from baseline has been suggested to define CIN. The reported incidence of CIN varies widely, ranging from 2 to 50%. This variability results from differences in the presence or absence of risk factors. With a retrospective analysis we evaluated the use of saline hydration plus N-acetyl cysteine (NAC) to prevent CIN in a low-risk population of patients undergoing coronary artery angiography compared with an historic low risk group not treated. From January 2009 to December 2009, 152 consecutive patients who underwent coronary artery angiography with a low osmolarity contrast agent were enrolled in our study, and compared with an historic control group consisting of 172 low-risk patients. Nephrotoxic drugs such as diuretics, ACE-I and ARBs were stopped at least 24 h before the procedure. Inclusion criteria to define low-risk population were the absence of: diabetes, age >65 years, or baseline creatinine >1.4 mg/dl. We have treated group A (152 patients, 47.3%) with a saline hydration (1 ml/kg/h) plus N-acetyl cysteine 600 mg 12 h before and 12 h after the procedure; group B (group control of 170 patients, 52.7%) were not treated. The overall incidence of CIN was 7.1% (23 patients). In particular, the incidence of CIN was 2.6% (4 patients) in the group A and 11.2% (19 patients) in the group B (p = 0.002). In the multivariate analysis, including risk factor such as age, hypertension, hypercholesterolemia, current smoking habit baseline creatinine level, contrast index and hydration, the last variable was the only one inversely correlated independently with the incidence of CIN (p = 0.001). In conclusion, intravenous hydration with saline and NAC is an effective and low cost tool in preventing CIN in patients undergoing coronary artery angiography, and, according to the current guidelines, should be used in all high-risk patients for CIN. Our results show that even in patients at low risk, hydration with saline 0.9% plus NAC is useful and significantly reduces the incidence of CIN.

Biventricular myocardial adaptation to different training protocols in competitive master athletes.

BACKGROUND: Conflicting data have been reported about the nature (physiologic versus pathologic) of left ventricular (LV) hypertrophy in master athletes. AIM OF THE STUDY: To analyze LV and right ventricular (RV) myocardial function in master athletes with LV hypertrophy induced by either endurance or strength training. METHODS: Standard Doppler echo and colour Doppler Myocardial Imaging (DMI) of LV and of RV basal lateral walls were performed in 40 competitive master (>45 years) endurance athletes (ATE), in 20 master strength-trained athletes (ATS) and 25 age-matched healthy sedentary subjects, all males. By use of DMI, the following parameters of myocardial function were assessed: systolic peak velocities, precontraction time, contraction time, early (E(m)) and late (A(m)) diastolic peak velocities, E(m)/A(m) ratio, relaxation time. RESULTS: The two groups were comparable for age, but ATS at rest showed higher heart rate, systolic blood pressure, and body surface area. LV mass index did not significantly differ between the two groups of athletes. However, ATS showed increased wall thickness and relative wall thickness, while LV stroke volume and both LV and RV end-diastolic diameters were greater in ATE. All transmitral and transtricuspid Doppler indexes were higher in ATE. DMI analysis showed in ATE higher E(m) and E(m)/A(m) ratio at the level of both RV and LV lateral walls. In the overall population of athletes, linear regression models evidenced independent positive association of RV peak E(m) velocity with both LV stroke volume and maximal workload achieved by bicycle ergometer (both p<0.001). CONCLUSIONS: RV early diastolic myocardial function is positively influenced by preload increase in master athletes and represents an independent determinant of cardiac performance during physical effort. Therefore, colour DMI may be taken into account to distinguish different cardiac adaptation to either endurance or strength sport training in master athletes.