Non-invasive cardiac output determination by two-dimensional independent Doppler during and after cardiac surgery.

PURPOSE: This study was to compare noninvasive measurement of cardiac output (CO) using a novel Doppler technique with invasive CO measurements in the postcardiac surgical intensive care unit. DESCRIPTION: Thirty-six patients (67.2 +/- 10 years, New York Heart Association functional class 3.1 +/- 0.3) undergoing coronary revascularization were prospectively examined postoperatively. One hundred eighty paired CO and stroke volume measurements were compared from the noninvasive USCOM device (Sydney, Australia) and the invasive Swan-Ganz catheter at varying COs. Eighteen measurements were performed intraoperatively by direct insonation of the right ventricular outflow tract. EVALUATION: Mean noninvasive and invasive CO values were 5.15 +/- 1.98 L/min and 4.92 +/- 2.0 L/min, respectively (r = 0.870; p < 0.01). The mean difference between methods was -0.23 +/- 1.01 L/min greater than a range of CO values from 2.5 to 9.9 L/min. Mean central venous saturation percentage was 72 +/- 9%, correlating with both noninvasive and invasive CO (r = 0.474 and 0.606, respectively, p < 0.01). Intraoperatively, both direct and invasive CO were identical. CONCLUSIONS: Using the ultrasonic cardiac output monitoring (USCOM) device it is possible to determine noninvasive beat-to-beat CO in postcardiac surgery patients without the possible complications associated with invasive right heart catheterization. The USCOM CO and stroke volume showed a very good agreement with invasive Swan-Ganz measures and correlated with central venous saturation percentage.

Palmar microcirculation after harvesting of the radial artery in coronary revascularization.

PURPOSE: To evaluate real-time parameters of palmar microcirculation before and after harvesting of the radial artery in coronary revascularization using a laser Doppler flowmetry and remission spectroscopy system (O2C). DESCRIPTION: Fifteen patients (11 males, 54 +/- 4 years, mean New York Heart Association [NYHA] class of 2.3 +/- 0.3) were prospectively scheduled with control measurements of the fingertips of D1, D3, and D5 at base line, after suprasystolic, and after selective radial or ulnar compression for tissue oxygen saturation (SO2), postcapillary venous recombinant hemoglobin (rHb) concentration, superficial (2 mm) blood flow, and deep (8 mm) blood flow. EVALUATION: Preoperatively during suprasystolic compression SO2 decreased significantly for the fingertips of D1, D3, and D5 by -58%, -74%, and -63%, respectively (p < 0.05). Radial compression reduced SO2 for all fingertips (-12%, -14%, and -16%), as did ulnar compression (-24%, -18%, and -10%). rHb did not change significantly for either compression type. Superficial and deep blood flow decreased significantly after suprasystolic and only slightly after radial and ulnar compression at either side. No side differences were noted. After radial artery harvesting, microcirculatory parameters did not change considerably versus preoperatively. CONCLUSIONS: Radial artery harvesting does not remarkably change microcirculatory parameters of the hand. The O2C system is a safe and quantitative method to assess both preoperatively and postoperatively the palmar microcirculation and therefore adds further functional clinical information.

Impact of multivessel coronary artery disease on outcome after isolated minimally invasive bypass grafting of the left anterior descending artery.

BACKGROUND: The outcome in patients treated surgically for coronary artery disease is known to be influenced by the extent of the disease. Whether this factor also has an effect in patients undergoing isolated minimally invasive revascularization of the left anterior descending (LAD) artery using the internal thoracic artery (ITA) (MIDCAB) has not been looked at. Thus, this study sought to evaluate the impact of multivessel disease (MVD) on midterm outcome after MIDCAB. METHODS: From 1996 to 1999, 411 patients received a MIDCAB at our institution and were now followed up. Isolated disease of the LAD (SVD -single vessel disease) was presented in 262 patients (63.7%) and 149 patients (36.3%) had MVD at the time of operation. The reasons for apparent incomplete revascularization in patients with MVD were very small target vessels (< 1.0-mm diameter), stenoses of less than 50%, distal localization of the stenoses, long-term patency after angioplasty, or an extensive risk for sternotomy and(or) cardiopulmonary bypass. The midterm outcome was evaluated by questionnaires sent to the patients and their physicians. RESULTS: The mean follow-up was 29.4 +/- 11.1 months. The incidence of myocardial infarction was significantly higher in MVD as compared to SVD patients (8.1% vs 1.9%, p = 0.04). Patients with MVD had significantly more subsequent percutaneous transluminal coronary angioplasty (10.7% vs 5.3%, p = 0.049) and a similar number of repeat surgical revascularizations as compared to SVD patients. Patients with MVD had a significantly higher total 3-year mortality as compared to SVD patients by Kaplan-Meier estimate (8.7% vs 3.1%, relative risk [RR] = 2.56, p = 0.011). The 3-year cardiac mortality was significantly higher in patients with MVD as compared to SVD (4.0% vs 0.4%, RR = 9.48, p = 0.0054). After adjustment of baseline characteristics by Cox regression analysis, the 3-year risk of cardiac death was significantly higher in the MVD groups (RR = 2.2, confidence interval [CI] 95%: 1.8 to 4.65, p = 0.029). CONCLUSIONS: Patients with isolated disease of the LAD appear to benefit from ITA grafting in the form of a MIDCAB procedure. Here, it should be an approach of choice. The results show that MVD is an independent risk factor for outcome in patients undergoing a MIDCAB procedure. Nevertheless, the midterm morbidity and mortality in MVD patients after a MIDCAB procedure where the LAD is the only target vessel for interventional or surgical treatment is acceptable despite a higher morbidity than in SVD patients.

Impact of diabetes on outcome following isolated minimally invasive bypass grafting of the left anterior descending artery.

BACKGROUND: The outcome in patients treated by conventional coronary artery bypass grafting (CABG) for coronary artery disease is negatively influenced by the presence of diabetes. The relative effect of diabetes in patients undergoing isolated minimally invasive revascularization of the left anterior descending artery (LAD) using the internal thoracic artery (ITA) has as yet not specifically been looked at. Thus, this study sought to evaluate the impact of diabetes on mid-term outcome following minimally invasive coronary artery bypass grafting (MIDCAB). METHODS: From 1996 to 1999, 411 patients received a MIDCAB procedure at our institution and were now followed up. In this study population there were 63 diabetic patients (15.3%) and 348 nondiabetic patients (84.7%). Isolated proximal stenoses or an occlusion of the LAD were present in 262 patients (63.7%), whereas 149 (36.3%) had multi-vessel disease (MVD) at the time of the MIDCAB procedure. The clinical outcome was evaluated by questionnaires sent to the patients and their physicians. RESULTS: The mean follow-up was 29.4 +/- 11.1 months. The incidence of myocardial infarction was significantly higher in diabetics as compared to nondiabetics (9.5% vs 3.2%, p = 0.034). Diabetics and nondiabetics had similar rates of subsequent revascularization procedures during follow-up. Cumulative total survival of diabetic and nondiabetic patients was not statistically different. The 3-year cardiac mortality was however significantly higher in diabetic than in nondiabetic patients if MVD was initially present (Kaplan-Meier estimate: 10.7% vs 2.5%, relative risk [RR] = 5.5, p = 0.017 by log-rank test). The 3-year cardiac mortality in diabetic and nondiabetic patients with isolated disease of the LAD (single vessel disease [SVD]) was not significantly different. After adjustment of baseline characteristics by Cox regression analysis the 3-year risk of cardiac death was significantly higher in the diabetic group (RR = 1.82, CI 95%:1.2 to 3.3, p = 0.045). CONCLUSIONS: The results support diabetes to be an independent risk factor for outcome in patients with MVD undergoing a MIDCAB procedure in analogy to those undergoing CABG procedures. Diabetics with isolated disease of the LAD, however, benefit out of proportion from this treatment modality.