Jaap R. Lahpor

Coronary artery bypass grafting without cardiopulmonary bypass using the octopus method: results in the first one hundred patients

OBJECTIVE Cardiopulmonary bypass and global cardiac arrest enable safe coronary artery bypass grafting but have adverse effects. In off-pump coronary bypass grafting, invasiveness is reduced, but anastomosis suturing is jeopardized by cardiac motion. Therefore the key to successful off-pump coronary bypass grafting is effective local cardiac wall stabilization. METHODS We prospectively assessed the safety and efficacy of the Octopus tissue stabilizer (Medtronic, Inc., Minneapolis, Minn.) in the first 100 patients selected for off-pump coronary bypass via full or limited surgical access. To immobilize and expose the coronary artery, two suction paddles (-400 mm Hg), fixed to the operating table-rail by an articulating arm, stabilized the anastomosis site. RESULTS One hundred forty-one grafts (96% arterial) were used to create 172 anastomoses (17% side-to-side), up to 4 per patient, on average 23 in the full access group (46 patients) and 1.2 in the limited access group (54 patients). Complications included conversion to cardiopulmonary bypass (2%), conversion from limited to full access (3%), myocardial infarction (4%), predischarge coronary reintervention (2%), and late coronary reintervention (1%). Median postoperative length of hospital stay was 4 days (limited access) or 5 days (full access). Rapid recovery allowed 96% of patients to resume social activities within 1 month. At the 6-month angiographic follow-up, 95% of anastomoses was patent. At the 2- to 22-month follow-up (mean, 13 months), 98 patients were in Canadian Cardiovascular Society class I and 2 patients were in class II. CONCLUSION These results suggest that off-pump coronary artery bypass grafting with the Octopus tissue stabilizer is safe. Early clinical outcome and patency rates warrant a randomized study comparing this methods with conventional coronary bypass grafting.

Noninvasive continuous arterial blood pressure monitoring with Nexfin

Background: If invasive measurement of arterial blood pressure is not warranted, finger cuff technology can provide continuous and noninvasive monitoring. Finger and radial artery pressures differ; Nexfin® (BMEYE, Amsterdam, The Netherlands) measures finger arterial pressure and uses physiologic reconstruction methodologies to obtain values comparable to invasive pressures. Methods: Intra-arterial pressure (IAP) and noninvasive Nexfin arterial pressure (NAP) were measured in cardiothoracic surgery patients, because invasive pressures are available. NAP-IAP differences were analyzed during 30 min. Tracking was quantified by within-subject precision (SD of individual NAP-IAP differences) and correlation coefficients. The ranges of pressure change were quantified by within-subject variability (SD of individual averages of NAP and IAP). Accuracy and precision were expressed as group average ± SD of the differences and considered acceptable when smaller than 5 ± 8 mmHg, the Association for the Advancement of Medical Instrumentation criteria. Results: NAP and IAP were obtained in 50 (34–83 yr, 40 men) patients. For systolic, diastolic, mean arterial, and pulse pressure, median (25–75 percentiles) correlation coefficients were 0.96 (0.91–0.98), 0.93 (0.87–0.96), 0.96 (0.90–0.97), and 0.94 (0.85–0.98), respectively. Within-subject precisions were 4 ± 2, 3 ± 1, 3 ± 2, and 3 ± 2 mmHg, and within-subject variations 13 ± 6, 6 ± 3, 9 ± 4, and 7 ± 4 mmHg, indicating precision over a wide range of pressures. Group average ± SD of the NAP-IAP differences were −1 ± 7, 3 ± 6, 2 ± 6, and −3 ± 4 mmHg, meeting criteria. Differences were not related to mean arterial pressure or heart rate. Conclusion: Arterial blood pressure can be measured noninvasively and continuously using physiologic pressure reconstruction. Changes in pressure can be followed and values are comparable to invasive monitoring.

Fractionated electrograms in dilated cardiomyopathy: Origin and relation to abnormal conduction

OBJECTIVES We sought to investigate the origin of the fractionated electrogram and its relations to abnormal conduction in cardiomyopathic myocardium. BACKGROUND Patients with dilated cardiomyopathy have a high incidence of ventricular tachycardias. Electrograms recorded in these patients are often fractionated. METHODS High resolution mapping (200-microM interelectrode distance) of the electrical activity was carried out in 11 superfused papillary muscles and 6 trabeculae from 7 patients who underwent heart transplantation because of dilated cardiomyopathy. Similar measurements were taken in four papillary muscles from dog hearts in which electrical barriers had been artificially made. Ten human preparations were studied histologically. RESULTS All preparations revealed sites with fractionated electrograms. In three human preparations, activation patterns showed a discernible line of activation block running parallel to the fiber direction. Fractionated electrograms were recorded at sites contiguous to the line of block. In five preparations, fractionated electrograms were recorded at sites where lines of block were not identified. In these preparations, electrical barriers consisted of short stretches of fibrous tissue. In the remaining nine preparations, fractionated electrograms were recorded, both from sites contiguous to distinct obstacles and sites without evidence of a barrier. CONCLUSIONS Our observations showed that fractionated electrograms recorded in myocardium damaged by cardiomyopathy were due to both distinct, long strands and short stretches of fibrous tissue. Delayed conduction was caused by curvation of activation around the distinct lines of block and by the wavy course of activation between the short barriers. The latter reflects extreme nonuniform anisotropy.

European results with a continuous-flow ventricular assist device for advanced heart-failure patients §

OBJECTIVE The HeartMate II (HM II) LVAD is a small, quiet, continuous-flow, left ventricular assist device (LVAD) for circulatory support in advanced heart-failure patients, with over 2000 implants worldwide. This article reports on the European experience with this device. METHODS The HM II was implanted in 571 patients at 64 European institutions. In 72% of cases (411 patients), implantation has taken place at least 6 months before the closing date of the study (1 August 2008). Patients (19% female, 70% ischaemic aetiology) were on maximum medical therapy, including inotropic support. Body surface area ranged from 1.30 to 2.50 m(2) and age from 14 to 75 years (mean: 51+/-14 years; n=115, 28% over age 60 years). The intention of support was to provide a bridge to transplantation (73%), destination therapy (21%) and a bridge to recovery (6%). Adverse events were documented in the first 53 patients - for obtaining the Conformité Européenne (CE) Mark (group A) - from a European multicentric study (Strüber et al. [Strüber M, Sander K, Lahpor J, Ahn H, Litzler P-Y, Drakos SG, Musumeci F, Schlensak C, Friedrich I, Gustafsson R, Oertel F, Leprince P. HeartMate II left ventricular assist device; early European experience. Eur J Cardiovasc Surg 2008;34(2):289-94.]: 101 patients) and from a single-centre study (UMCU, The Netherlands: 30 patients). RESULTS The mean support duration ranged from 0 to 1019 days with a mean of 236+/-214 days (249 patients: >6 months, 119: 1 year, 12: >2 years; total support time: 293 years). The overall survival to transplantation, recovery or ongoing device support at the end of the study was 69% (284) with an early mortality of 17.5% and late mortality of 13.5%. Of the surviving patients, 23% have been transplanted, 4% had their device removed after recovery of the left ventricle and 42% are still ongoing. Adverse events included bleeding (ranging from 42% in group C to 59% in group A), percutaneous lead infections (A: 0.19, B: 0.61 and C: 0.18 events per patient year), pocket infections (A: 0.08, B: 0.07 and C: 0.09 events per patient year), ischaemic stroke (A: 0.06, B: 0.09 and C: 0.04 events per patient year), haemorrhagic stroke (B: 0.07, C: 0.04 events per patient year) and transient ischaemic attacks (TIAs; A: 0.08, B: 0.02 and C: 0.13 events per patient year). CONCLUSIONS These results support the use of the HM II continuous-flow LVAD for long-term support as a bridge to transplantation and possibly for destination therapy. Future emphasis should focus on minimising adverse events such as infections, bleeding and neurological events.

Exercise Performance in Patients With End-Stage Heart Failure After Implantation of a Left Ventricular Assist Device and After Heart Transplantation An Outlook for Permanent Assisting?

OBJECTIVES We sought to study exercise capacity at different points in time after left ventricular assist device (LVAD) implantation and subsequent heart transplantation (HTx). BACKGROUND The lack of donor organs warrants alternatives for transplantation. METHODS Repeat treadmill testing with respiratory gas analysis was performed in 15 men with a LVAD. Four groups of data are presented. In group A (n = 10), the exercise capacities at 8 weeks and 12 weeks after LVAD implantation were compared. In group B (n = 15), the data at 12 weeks are presented in more detail. In group C (n = 9), sequential analysis of exercise capacity was performed at 12 weeks after LVAD implantation and at 12 weeks and one year after HTx. In group D, exercise performance one year after HTx in patients with (n = 10) and without (n = 20) a previous assist device was compared. RESULTS In group A, peak oxygen consumption (Vo2) increased from 21.3+/-3.8 to 24.2+/-4.8 ml/kg body weight per min (p < 0.003), accompanied by a decrease in peak minute ventilation/ carbon dioxide production (VE/Vco2) (39.4+/-10.1 to 36.3+/-8.2; p < 0.03). In group B, peak Vo2 12 weeks after LVAD implantation was 23.0+/-4.4 ml/kg per min. In group C, levels of peak Vo2 12 weeks after LVAD implantation and 12 weeks and one year after HTx were comparable (22.8+/-5.3, 24.6+/-3.3 and 26.2+/-3.8 ml/kg per min, respectively; p = NS). In group D, there appeared to be no difference in percent predicted peak Vo2 in patients with or without a previous LVAD (68+/-13% vs. 74+/-15%; p < 0.37), although, because of the small numbers, the power of this comparison is limited (0.45 to detect a difference of 10%). CONCLUSIONS Exercise capacity in patients with a LVAD increases over time; 12 weeks after LVAD implantation, Vo2 is comparable to that at 12 weeks and one year after HTx. Previous LVAD implantation does not seem to adversely affect exercise capacity after HTx.

HeartMate II left ventricular assist device; early European experience

OBJECTIVE The novel axial flow left ventricular assist device HeartMate II was introduced into clinical practice in Europe as part of the pilot study and after CE approval in November 2005. In order to get an overview of the use and performance of the device in Europe a group of investigators was founded to compare the initial results. METHODS In a retrospective analysis of the first 101 consecutive cases in Europe, data were collected with regard to postoperative outcome and severe adverse events and anticoagulation protocols. Results were stratified by intention to treat as a bridge to transplant or as chronic support therapy in heart failure (destination therapy). RESULTS In 70% of patients, the HeartMate II was intended as a bridge to transplant therapy, in 30%, it was used as a destination therapy device. The perioperative mortality post implant was 20% in the bridge to transplant patients and 7% in the destination therapy arm. However, after 1 year a comparable survival was observed in both groups (69% destination therapy, 63% bridge to transplant). Main causes of death were multiple organ failure (n=12) and cerebrovascular accidents (n=5). All, but one cerebrovascular accident occurred in the first 9 days after surgery. Only one other death was reported thereafter and there was no mechanical failure of the device. CONCLUSIONS Even in the early experience the HeartMate II was used as a chronic support device in a substantial number of patients in Europe. Although the total experience is still limited, the incidence of cerebrovascular accidents is very low and the survival beyond the perioperative period is excellent.

Randomized Comparison Between Stenting and Off-Pump Bypass Surgery in Patients Referred for Angioplasty

Background—Stenting improves cardiac outcome in comparison with balloon angioplasty. Compared with conventional surgery, off-pump bypass surgery on the beating heart without cardiopulmonary bypass may reduce morbidity, hospital stay, and costs. The purpose, therefore, was to compare cardiac outcome, quality of life, and cost-effectiveness 1 year after stenting and after off-pump surgery. Methods and Results—Patients referred for angioplasty (n=280) were randomly assigned to stenting (n=138) or off-pump bypass surgery. At 1 year, survival free from stroke, myocardial infarction, and repeat revascularization was 85.5% after stenting and 91.5% after off-pump surgery (relative risk, 0.93; 95% CI, 0.86 to 1.02). Freedom from angina was 78.3% after stenting and 87.0% after off-pump surgery (P =0.06). Quality-adjusted lifetime was 0.82 year after stenting and 0.79 year after off-pump surgery (P =0.09). Hospital stay after the initial procedure was 1.43 and 5.77 days, respectively (P <0.01). Stenting reduced overall costs by

Cerebrovascular complications of left ventricular assist devices

2933 (26.2%) per patient (

Comparison of functional capacity in patients with end-stage heart failure following implantation of a left ventricular assist device versus heart transplantation: results of the experience with left ventricular assist device with exercise trial.

8276 versus

Circulating growth differentiation factor‐15 correlates with myocardial fibrosis in patients with non‐ischaemic dilated cardiomyopathy and decreases rapidly after left ventricular assist device support

11 209; P <0.01). Stenting was more cost-effective in 95% of the bootstrap estimates. Conclusions—At 1 year, stenting was more cost-effective than off-pump surgery while maintaining comparable cardiac outcome and quality of life. Stenting rather than off-pump surgery, therefore, can be recommended as a first-choice revascularization strategy in selected patients.