Radial artery achieves better flowmetric results than saphenous vein in the elderly.

Due to the limited life expectancy and the supposed higher morbidity with complete arterial grafting, extensive arterial graft in the elderly is still questioned. It was the aim of this study to evaluate transit time flow and clinical, biochemical and echocardiographic results of elderly patients undergoing coronary artery bypass grafting (CABG) with either saphenous vein (SV) or radial artery (RA) employed as the second conduit of choice. The present study evaluates clinical and flowmetric results of a prospective series of elderly patients (>or=70 years old) undergoing RA CABG (75 patients, Group A) or SV CABG (163 patients, Group B) during isolated myocardial revascularization, performed either off-pump (OPCABG) and on-pump during the last 5 years at a single academic institution (between January 2003 and December 2007). Transit time flowmetric (TTF) maximum and mean flow, pulsatility index (P.I.), and graft flow reserve (GFR) were compared. Hospital outcome was analyzed. Clinical data were compared between the two groups and one-year follow-up was completed. The two groups showed comparable preoperative and intraoperative variables. When TTF analysis was considered, patients undergoing RA grafting demonstrated a significantly higher maximum (systolic) and mean flow compared to SV grafting, either in circumflex, diagonal, and right coronary territory. Pulsatility index was significantly lower in the RA group in circumflex, diagonal, and right coronary grafts. Furthermore, when GFR was calculated significantly higher values were found in RA conduits in the circumflex, diagonal, and right coronary grafts. Comparable troponin I leakage was detected between the two groups. Postoperative variables addressing hospital outcome were similar in the two groups. When echocardiographic data were analyzed, no differences were recorded in postoperative recovery of left ventricular ejection fraction and wall motion score index. One-year follow-up showed better freedom from acute cardiovascular events in the RA group (P = 0.04). Our data show that despite comparable clinical, biochemical, and echocardiographic results in elderly patients undergoing RA or SV grafting, better flowmetric results - in terms of GFR, mean flow, and pulsatility index - can be detected in arterial conduits.

Continuous coronary sinus perfusion reverses ongoing myocardial damage in acute ischemia.

Acute cardiogenic shock or cardiac arrest (CS/CA) before cardiopulmonary bypass (CPB) installation are life-threatening events in acute coronary syndromes. We evaluated whether continuous retrograde warm-blood perfusion(CRWBP) before aortic cross-clamping (ACC),with immediate CPB installation may improve hospital results in these dreadful events. Hospital outcome of 18 coronary artery bypass grafting (CABG) (Group A) with CS/CA before CPB, with immediate CPB installation and CRWBP,has been compared with 24 CABG (Group B) with CS/CA undergoing only immediate CPB installation. No differences have been detected in the mean time to establish CPB(P = 0.655). Electrocardiography normalized in a significantly higher number of CRWBP (P = 0.0001). Group B showed longer CPB (116.2 +/- 21.2 min vs. 157.8 +/- 32.4;P = 0.0001) and postoperative intra-aortic balloon pumping time course (36.2 +/- 5.9 h vs. 77.8 +/-13.2; P = 0.0001).CRWBP reduced postoperative acute myocardial infarction (P = 0.004) and damage (P = 0.033), death (P = 0.026),and need for high inotropic support (0% vs. 37.5%; P =0.003). Troponin I was significantly lower in Group A(P = 0.013 from coronary sinus; P

Intra-aortic balloon pumping recruits graft flow reserve by lowering coronary resistances.

BACKGROUND: The intra-aortic balloon pump (IABP) is used worldwide as an anti-ischemic strategy and to reduce myocardial workload. However, whether IABP augments coronary flow after coronary bypass via a passive increase in diastolic pressure or an active response of the coronary bed remains uncertain. METHODS: We analyzed transit-time flow measurements and the contemporary changes in coronary resistances obtained during 1:1 IABP and during its cessation in 144 consecutive patients receiving prophylactic IABP before isolated coronary artery bypass grafting (n=340 graft segments). RESULTS: Normally functioning grafts showed lower coronary resistances, greater percentage decrease in resistance, and greater increases in average maximum diastolic and mean flow during 1:1 IABP compared with IABP cessation (P<.001). Arterial and sequential saphenous vein grafts showed better flowmetry and greater reductions in coronary resistances compared with single venous grafts. Accordingly, graft flow reserve (defined as mean flow during 1:1 IABP/mean flow with IABP off) was recruited (graft flow reserve >1) during 1:1 IABP in all normally functioning grafts, with higher values in single arterial or sequential saphenous vein grafts than in single venous grafts (both P<.001). Coronary resistances were higher in 7 failed grafts versus normal-functioning grafts at baseline; these did not decrease during 1:1 IABP and showed worse transit-time flow results. CONCLUSIONS: IABP recruits graft flow reserve by lowering coronary resistance in functioning grafts. Arterial and sequential venous grafts showed greater reduction in coronary resistance compared with single saphenous grafts.

Radial artery graft flowmetry is better than saphenous vein on postero-lateral wall.

BACKGROUND: Although general agreement exists on internal mammary graft as the first conduit, the second choice is still questioned. Despite radial artery (RA) grafting has been suggested, saphenous veins (SV) continue to be extensively used. METHODS: A prospective series of isolated RA-CABG (150 patients) or SV-CABG (180 patients), performed either off-pump (OP-CABG) and on-pump (CPB-CABG), in diabetics and non-diabetics, in elderly and young patients, during the last 5-years at a single institution were evaluated. RA was harvested with harmonic scalpel, flowmetry was performed with a transit-time flowmeter (TTF). Graft flow reserve (GFR) was calculated with intra-aortic balloon-pump. Follow-up was collected by outpatient clinic database or by telephone interview with general practitioners. RESULTS: The 2 groups showed comparable preoperative and intraoperative variables. Mortality, morbidity, myocardial infarction, troponin I leakage, and echocardiographic parameters were comparable (p=NS). RA-CABG demonstrated significantly higher TTF maximum, mean and minimum flow (p<.001) with lower Pulsatility Index (p<.001), either in the circumflex and the right coronaries. Compared to SVG-grafting, significantly higher GFR was found in RA-CABG on the circumflex (p=.001) and right (p=.028) coronaries. 38.1+/-0.9 SE months follow-up resulted in higher survival and freedom from cardiac events in RA-CABG. Better TTF and GFR were demonstrated in OP-CABG, CPB-CABG, diabetics, non-diabetics, either on the circumflex and right coronary systems (p<.05). Better mean flow was detected in RA-CABG on the circumflex in the elderly (p=.04) and the young (p=.05). CONCLUSIONS: RA-CABG demonstrated better TTF and GFR results compared to SV-CABG. These data may contribute to explain the survival benefit of arterial revascularization already reported.

In vivo functional flowmetric behavior of the radial artery graft: is the composite Y-graft configuration advantageous over conventional aorta-coronary bypass?

INTRODUCTION: Intraoperative flowmetric results of different configurations (Y-graft or aorta-coronary) of radial artery grafts have been poorly investigated. METHODS: We report the results of an observational study designed to analyze transit-time flow measurements at baseline and during 1:1 intra-aortic balloon pumping in 114 consecutive patients receiving the radial artery as a aorta-coronary bypass (group A, 72 patients) or as a Y-graft with the left internal thoracic artery (group B, 42 patients). Graft flow reserve, recruited by 1:1 intra-aortic balloon pumping) greater than 1 indicated recruitment of surplus graft flow. Results were stratified by grafted territory and surgical technique. RESULTS: Hospital outcome was comparable. Baseline transit-time flow results were similar between the 2 groups in terms of maximum diastolic flow, minimum systolic flow, mean flow, and pulsatility index. Graft flow reserve was not recruited by intra-aortic balloon pumping in 3 (2.7%) malfunctioning single aorta-oronary radial artery bypass grafts (P = .005 versus successful radial artery bypass grafts). Graft flow reserve was recruited (>1) by intra-aortic balloon pumping in the remaining 111 patent radial artery bypass grafts. Y-grafts showed higher maximum diastolic flow P < .0001), mean flow (P < .0001), graft flow reserve (P < .0001), percentage improvement of maximum diastolic flow (P < .0001), and of mean flow (P < .0001) compared with aorta-coronary radial artery bypass grafts. These results were confirmed for the right coronary (P < or = .004) and the circumflex territory (P < or = .001), for off-pump (P < or = .008) or cardiopulmonary bypass (P < .0001) and for patients undergoing isolated bypass grafting (P < .0001). CONCLUSIONS: Intraoperative flows of radial artery bypass grafts showed comparable baseline results in single aorta-coronary conduits and Y-grafts. Graft flow reserve recruited by intra-aortic balloon pumping was higher in Y-conduits, regardless of the grafted territory and the perfusion strategy chosen. Failed radial artery bypass grafts did not improve transit-time flow results during 1:1 intra-aortic balloong pumping nor showed any recruitment of graft flow reserve.

Intraoperative bypass graft flow in intra-aortic balloon pump-supported patients: differences in arterial and venous sequential conduits.

BACKGROUND: The intra-aortic balloon pump is used worldwide as an anti-ischemic strategy. However, little is known about the modifications of the graft flowmetry during use of intra-aortic balloon pump. METHODS: An observational study aimed at analyzing transit-time flow measurements during 1:1 intra-aortic balloon pump use and during its cessation in 138 consecutive patients using intra-aortic balloon pump before coronary artery bypass grafting (n = 442 graft segments) was reported. RESULTS: In normally functioning grafts, the mean diastolic and mean blood flow improved significantly during 1:1 intra-aortic balloon pump use compared with during intra-aortic balloon pump cessation (P < .001), although mean and diastolic arterial pressures were significantly lower (P = .001). Arterial and sequential saphenous vein grafts showed greater improvements in mean diastolic and mean flow compared with single venous grafts. Surplus graft flow (defined as mean flow during 1:1 intra-aortic balloon pump use/mean flow with intra-aortic balloon pump off) was recorded (surplus graft flow > 1) during 1:1 intra-aortic balloon pump use in all normally functioning grafts, with higher values in single arterial or sequential saphenous vein grafts versus single venous grafts (both P < .001). In the 9 cases of graft failure, the mean diastolic, mean systolic, and mean flow were significantly lower and the pulsatility index greater, compared with normally functioning grafts (all P