The kinetics and specificity of lymphocyte infiltration of cardiac allografts in unmodified and cyclosporin-treated rats.

Lymphocyte infiltration of heart grafts has been monitored using pulses of Indium-111-labelled syngeneic lymphocytes. The cells were injected into cyclosporin (CSA)-treated or untreated rats that had received an allograft 1, 2, 4, 6, and 8 days previously Accumulation of the labelled cells in the graft was measured 24 hr after injection, and was compared with that in the animal's own heart. For the first three days after grafting, Indium-111-labelled lymphocytes accumulated to the same extent in the grafts of untreated and CSA-treated rats. However, the substantial rapid increase in lymphocyte accumulation in the graft that occurs in the untreated recipient between days 4 and 5 did not occur in CSA-treated recipients. From day 5 until day 9 the accumulation of labelled cells in CSA-maintained grafts was not greater than in syngeneic non-rejecting grafts, and it was significantly less than in the untreated rejecting grafts. At early times after grafting, removal from the labelled cell population of lymphocytes with reactivity against the histocompatibility antigens of the graft resulted in a reduction in the extent to which these lymphocytes accumulated in the graft.

Early to midterm results with the radial artery in coronary artery bypass grafting following autotransplantation without pharmacological manipulation.

BACKGROUND: In our unit when the radial artery is used as a conduit for myocardial revascularization routine, postoperative calcium-channel blockade is not practised. To preserve the radial artery, it is freed from the surrounding structures together with its venae commitantes and then left, in situ, in circulation, until needed for grafting. We evaluated the early to midterm patency of the radial artery using this strategy in our patients. METHODS: We analysed prospectively collected data on 690 consecutive patients who had isolated primary coronary artery bypass grafting performed between June 1999 and February 2003 with at least one conduit being a radial artery. RESULTS: Radial arteries were used for 851 of 2150 distal anastomoses (39.6%). Median follow-up was 399 days (range 20-1323) and was 99.9% complete. Early mortality was 2.0% (14). Late mortality was 3.0% (21), 12 late deaths were not cardiac related. Nine patients (1.4%) had angiography on clinical grounds a mean of 238 days (range 0-511) postoperatively. Six coronary artery territories were inadequately supplied by their radial artery grafts. Kaplan-Meier event-free survival was 94% and 90% at 1 and 3 years, respectively. CONCLUSIONS: The results of coronary artery bypass grafting using the radial artery in our institution compare favourably with those of other contemporary workers. It is safe to leave the radial artery in situ in the circulation until it is required for grafting. The absence of postoperative pharmacological manipulation of the radial artery does not appear to affect early or midterm outcome.

Troponin T release with warm and cold cardioplegia.

Cardiac troponin T (cTnT) levels were measured in 41 patients undergoing elective coronary artery surgery. Twenty-one patients received continuous warm antegrade blood cardioplegia to maintain asystole whilst 20 patients received antegrade cold blood cardioplegia intermittently. Serum levels of cTnT were determined preoperatively and at 0, 6, 12 and 18 h postbypass. Peak cTnT levels and total cTnT release (calculated from the area under the curve postoperatively) were found to be significantly higher (p < 0.05: Mann-Whitney) when cold cardioplegic solutions were used. Continuous warm cardioplegia results in lower cTnT release than intermittent cold blood cardioplegia suggesting that the former may provide better myocardial preservation.