Feasibility of combined percutaneous transluminal angioplasty and minimally invasive direct coronary artery bypass in patients with multivessel coronary artery disease

Current Treatment Options for the Failing Fontan Circulation

The Fontan operation was introduced in 1968. For congenital malformations, where biventricular repair is unsuitable, the Fontan procedure has provided a long-term palliation strategy with improved outcomes compared to the initially developed procedures. Despite these improvements, several complications merely due to a failing Fontan circulation, including myocardial dysfunction, arrhythmias, increased pulmonary vascular resistance, protein-losing enteropathy, hepatic dysfunction, plastic bronchitis, and thrombo-embolism, may occur, thereby limiting the life-expectancy in this patient cohort. This review provides an overview of the most common complications of Fontan circulation and the currently available treatment options.

Hybrid myocardial revascularization

Background

In patients with advanced coronary artery disease (CAD), coronary artery bypass grafting (CABG) is associated with improved long-term outcomes while percutaneous coronary intervention (PCI) is associated with lower periprocedural complications. A new approach has emerged in the last decade that attempts to reap the benefits of bypass surgery and stenting while minimizing the shortcomings of each approach, hybrid myocardial revascularization (HMR).Three strategies for timing of the hybrid revascularization exists, each with their own inherent advantages and shortcomings: (1) CABG followed by PCI, (2) PCI followed by CABG, or (3) simultaneous CABG + PCI in a hybrid suite.

Studies

The results of the first randomized control trial comparing HMR (CABG first) and standard CABG, POL-MIDES (Prospective Randomized PilOt Study EvaLuating the Safety and Efficacy of Hybrid Revascularization in MultIvessel Coronary Artery DisEaSe), show HMR was feasible for 93.9% of patients whereas conversion to standard CABG was required for 6.1%. At 1 year, both groups had similar all-cause mortality (CABG 2.9% vs. HMR 2%) and major adverse clinical event (MACE)-free survival rates (CABG 92.2% vs. HMR 89.8%). Results of observational and comparative studies show that minimally invasive HMR procedures in patients with multivessel CAD carry minimal perioperative mortality risk and low morbidity and do not increase the risk of postoperative bleeding. The advantage they offer in comparison to classical surgical revascularization is indeed faster rehabilitation and patient's return to normal life.

Conclusion

Hybrid myocardial revascularization has been developed as a promising technique for the treatment of high-risk patients with CAD. Hybrid revascularization using minimally invasive surgical techniques combined with PCI offers to a part of patients an advantage of optimal revascularization of the most important artery of the heart, together with adequate myocardial revascularization in a relatively delicate way. Indeed, to patients with high operative risk of standard surgery, it offers an alternative which should be considered carefully.

The Miracle Baby Grows Up: Hypoplastic Left Heart Syndrome in the Adult

PURPOSE OF REVIEW

Hypoplastic left heart syndrome (HLHS) is characterized by underdevelopment of the mitral valve, left ventricle, and aorta and is ultimately palliated with a single-ventricle repair. Universally fatal in infancy prior to the advent of modern surgical techniques, the majority of HLHS patients will now reach adulthood. However, despite improvements in early survival, the HLHS population continues to face significant morbidity and early mortality. This review delineates common sources of patient morbidity and highlights areas in need of additional research for this growing segment of the adult congenital heart disease population.

RECENT FINDINGS

It has become increasingly clear that palliated adult single ventricle patients, like those with HLHS, face significant life-long morbidity from elevated systemic venous pressures as a consequence of the Fontan procedure. Downstream organ dysfunction secondary to elevated Fontan pressures has the potential to significantly impact long-term management decisions, including strategies of organ allocation. Because of the presence of a morphologic systemic right ventricle, HLHS patients may be at even higher risk than other adult patients with a Fontan. Because the adult HLHS population continues to grow, recognition of common sources of patient morbidity and mortality is becoming increasingly important. A coordinated effort between patients and providers is necessary to address the many remaining areas of clinical uncertainty to help ensure continued improvement in patient prognosis and quality of life.

Lateral Atrial Tunnel Fontan Operation Predisposes to the Junctional Rhythm

The goal of the study was to compare the early postoperative course after fenestrated lateral atrial tunnel (LT) and non-fenestrated extracardiac conduit (EC) Fontan operation (FO) in a single center where both techniques were parallelly used. Between 2004 and 2012, 56(32.7%) children underwent LT and 113(66.1%) EC FO. The mean age was 3.7 ± 2.9 years and mean weight was 14.6 ± 7.3 kg. The most common malformation was hypoplastic left heart syndrome (50.9%). The general approach was to perform LT in children after hemi-Fontan operation and EC in patients after Glenn anastomosis. Medical records were retrospectively reviewed. The hospital survival was 100%. In EC group, cardiopulmonary bypass time (CPB) was shorter (p = 0.004) and less patients needed aortic cross-clamping (p < 0.001). Children after EC stayed longer in the hospital (p = 0.016) and manifested more often prolonged effusions (p = 0.038). The incidence of all forms of junctional rhythm was higher in the LT group, early postoperatively (p < 0.001), during hospitalization (p = 0.004) and at discharge (p < 0.001). Children after LT required more often temporary pacemaker stimulation (p < 0.001). Patients without postoperative normofrequent sinus rhythm had longer CPB time (p = 0.008) and were more often operated on with aortic cross-clamping (p = 0.028). Lateral atrial tunnel Fontan operation with fenestration facilitates early adaptation to the total passive pulmonary flow, but predisposes the patients to the loss of sinus rhythm. The crucial role in the preservation of sinus rhythm plays the last step of the multistage surgery of the single ventricle malformations, probably not only the surgical technique but also factors associated with the cardiopulmonary bypass.

Myocardial Preconditioning: Characteristics, Mechanisms, and Clinical Applications

Perioperative myocardial ischemia and dysfunction re main prevalent after cardiac surgery despite the use of conventional measures to provide myocardial protec tion. Myocardial preconditioning is a powerful, endog enously regulated means of myocardial protection that may also have some clinical usage for patients undergo ing cardiac surgical procedures. The paradoxical con cept of using ischemia as a stimulus for myocardial protection has been studied extensively in animals and humans. The specific characteristics and constituents of preconditioning have been well identified. The mecha nism remains to be completely elucidated due to differ ences among species and experimental models. Some pharmacologic agents are capable of mimicking the classic mechanism of ischemic preconditioning. Pharma cologic and ischemic preconditioning may have signifi cant clinical use and therapeutic efficacy as a means of providing myocardial protection during cardiac surgery, especially in procedures that do not use cardioplegia and cardiopulmonary bypass, such as minimally inva sive coronary artery bypass grafting. This article re views the characteristics, mechanisms, potential clini cal applications, and therapeutic efficacy of myocardial preconditioning.

Heart rate variability in children with Fontan circulation: lateral tunnel and extracardiac conduit

The technique in Fontan surgery has developed from the lateral tunnel (LT) toward the extracardiac conduit (EC) used to reduce long-term complications such as atrial arrhythmia and sinus node dysfunction. Heart rate variability (HRV) examines cardiac nervous activity controlling the sinus node. This study aimed to investigate HRV in a cohort of children with univentricular hearts, focusing on the relation between HRV and surgical procedure. For 112 children with Fontan circulation, HRV was analyzed using power spectral analysis. Spectral power was determined in three regions: very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) regions. Patients were compared with 66 healthy controls subject. Patients with LT were compared with patients who had EC. The children with Fontan circulation showed a significantly reduced HRV including total power (P < 0.0001), VLF (P < 0.0001), LF (P < 0.0001), and HF (P = 0.001) compared with the control subjects. The LT and EC patients did not differ significantly. Reduced HRV was found in both the LT and EC patients. In terms of HRV reduction, EC was not superior to LT.

Development and application of a LC-MS/MS method to quantify basal adenosine concentration in human plasma from patients undergoing on-pump CABG surgery

A sensitive and robust LC-MS/MS method was developed to quantify basal adenosine concentrations in human plasma of patients undergoing on-pump coronary artery bypass grafting (CABG) surgery. A strong cation exchange (SCX) monolithic cartridge was used to enrich analyte, improve robustness, and reduce biological complexity. A simple modifier-free mobile phase was employed to improve sensitivity and reproducibility. This method exhibits consistent precision and accuracy, and the RSDs or REs of all the intraday and interday determinations were within 10%. The calibration curve was linear across the examined dynamic range from 1nM to 500nM (r(2)=0.996). LOD and LOQ were determined to be 0.257nM and 0.857nM respectively, while LLOQ was below 10nM. This method was used to monitor changes of adenosine levels in patient plasma drawn intraoperatively during on-pump CABG surgery. The analysis of 84 patients revealed that the mean concentration of adenosine in coronary sinus plasma after cardiopulmonary bypass (CPB) is higher than that in coronary sinus before CPB (p=0.0024; two-tailed t-test) and that in radial artery plasma after CPB (p=0.0409; two-tailed t-test). These findings suggest that the equilibrium between adenosine production and elimination has favored the elevation of adenosine basal level during on-pump CABG surgery and the change is specific to heart tissues. Evaluation of adenosine with a sensitive and robust analytical method has important implications on providing consistent results and meaningful insights into adenosine regulation, as well as its steady state and sustained action on the heart. Relating patient characteristics or clinical outcomes with basal adenosine concentration can be used to optimize the CABG-CPB maneuver by regulating adenosine level via pharmacological intervention, and differentiating adenosine's contribution to cardioprotection from other modulatory factors.

Management of postoperative pediatric cardiac arrhythmias: current state of the art

Postoperative arrhythmias in the pediatric population remain a significant source of morbidity and mortality despite advances in surgical techniques. Although our understanding of these arrhythmias has improved, the number of therapeutic options to treat them has not increased significantly in recent years. However, in the specific case of bradyarrhythmias, the use of pacemakers has reduced morbidity and mortality significantly. Additionally, various antiarrhythmic medications, in conjunction with physiologic maneuvers when necessary, have improved our ability to treat postoperative tachyarrhythmias. The prompt recognition and proper treatment of postoperative arrhythmias can reduce morbidity and mortality for these patients.

Four decades of Fontan palliation

The Fontan palliation was introduced in 1968 to treat cardiac malformations unsuitable for biventricular repair. This procedure has transformed the surgical management of congenital heart disease. In this Review, we reflect on the outcomes and clinical problems associated with this unique circulation after more than 40 years of experience. We also summarize the evolution of the Fontan procedure, highlight the long-term clinical issues and their management, and consider future expectations of a circulation driven by a single ventricle with the systemic and pulmonary blood flow in series rather than in parallel.

Coronary artery bypass grafting without full sternotomy

Coronary artery bypass grafting is performed without full sternotomy in selected patients because it is less invasive. Left internal thoracic artery-left anterior descending artery bypass (LITA-LAD bypass) via a small left anterior thoracotomy is a well established procedure, which achieves good graft patency with low mortality and morbidity rates. Multiple revascularization is possible with a limited lateral thoracotomy or L-figure approach. Axillary-coronary bypass and right gastroepiploic artery-right coronary artery bypass (RGEA-RCA bypass) are alternative methods, especially for redo surgery, in selected patients.

Comparison of economic and patient outcomes with minimally invasive versus traditional off-pump coronary artery bypass grafting techniques

BACKGROUND

Minimally invasive coronary artery bypass grafting (miniCABG) decreases in-hospital morbidity versus traditional sternotomy CABG. We performed a prospective cohort study (NCT00481806) to assess the impact of miniCABG on costs and metrics that influence quality of life after hospital discharge.

METHODS

One hundred consecutive miniCABG cases performed using internal mammary artery (IMA) grafting +/- coronary stenting were compared with a matched group of 100 sternotomy CABG patients using IMA and saphenous veins, both treating equivalent number of target coronaries (2.7 vs. 2.9), off-pump. We compared perioperative costs, time to return to work/normal activity, and risk of major adverse cardiac/cerebrovascular events (MACCE) at 1 year: myocardial infarction (elevated troponin or EKG changes), target vessel occlusion (CT angiography at 1 year), stroke, or death.

RESULTS

For miniCABG, robotic instruments and stents increased intraoperative costs; postoperative costs were decreased from significantly less intubation time (4.80 +/- 6.35 vs. 12.24 +/- 6.24 hours), hospital stay (3.77 +/- 1.51 vs. 6.38 +/- 2.23 days), and transfusion (0.16 +/- 0.37 vs. 1.37 +/- 1.35 U) leading to no significant differences in total costs. Undergoing miniCABG independently predicted earlier return to work after adjusting for confounders (t = -2.15; P = 0.04), whereas sternotomy CABG increased MACCE (HR, 3.9; 95% CI, 1.4-7.6), largely from lower target-vessel patency.

CONCLUSIONS

MiniCABG shortens patient recovery time, minimizes MACCE risk at 1 year, and showed superior quality and outcome metrics versus standard-of-care CABG. These findings occurred without increasing costs and with superior target vessel graft patency.

Hybrid approach for complex coronary artery and valve disease: a clinical follow-up study

BACKGROUND

For patients suffering from complex coronary artery disease (CAD) with or without concomitant valve disease, no evidence is available in the current guidelines to propose a predefined treatment regimen. We sought to assess the clinical impact of an unconventional or extended definition of the hybrid approach that combines percutaneous coronary intervention (PCI) and cardiac surgery in subjects suffering from severe solitary CAD or combined with valve disease.

METHODS AND RESULTS

Between July 2002 and August 2004, 18 consecutive patients with complex CAD with or without significant valve disease who qualified for a hybrid approach were enrolled in a clinical follow-up study. Four patients eventually did not complete the proposed interventions. One patient refused treatment after inclusion, one patient died before treatment could be undertaken and two patients died after surgery but before PCI. In the other 14 cases combined treatment was technically successful. After a mean follow-up period of 15alpha5 months two patients had died, one due to sudden cardiac death and one of a noncardiac cause. No other major adverse clinical events were reported. A marked increase in quality of life was reported in those alive.

CONCLUSION

Hybrid approach had a favourable long-term outcome in patients with complex cardiovascular disease undergoing successful treatment; however, this was observed at the expense of significant periprocedural mortality in these high-risk subjects. Therefore we believe that hybrid approaches may provide an alternative for selected cases. (Neth Heart J 2007;15:329-4.).

Simultaneous hybrid coronary revascularization reduces postoperative morbidity compared with results from conventional off-pump coronary artery bypass

OBJECTIVES

Less-invasive options are available for surgical treatment of multivessel coronary artery disease. We hypothesized that stenting combined with grafting of the left anterior descending artery with the left internal thoracic artery through a minithoracotomy (hybrid procedure) would provide the best outcome.

METHODS

Patients with equivalent numbers of coronary lesions (2.8 +/- 0.4) underwent either hybrid (n = 15) or off-pump coronary artery bypass through a sternotomy (n = 30). Early and 1-year outcomes were compared. Blood drawn from the aorta and coronary sinus immediately postoperatively was analyzed for activation of coagulation (prothrombin fragment 1.2 and activated Factor XII), myocardial injury (myoglobin), and inflammation (interleukin 8) by using an enzyme-linked immunosorbent assay. Target-vessel patency was determined by means of computed tomographic angiographic analysis.

RESULTS

The hybrid procedure was associated with significantly shorter lengths of intubation and stays in the intensive care unit and hospital and perioperative morbidity (P < .05). Intraoperative costs were increased but postoperative costs were reduced for the hybrid procedure compared with off-pump coronary artery bypass through a sternotomy. As a result, overall total costs were not significantly different between the groups. After adjusting for potential confounders, assignment to the hybrid group was an independent predictor of shortened time to return to work (t = -2.12, P = .04). Patient satisfaction after the hybrid procedure, as judged on a 6-point scale, was greater versus that after off-pump coronary artery bypass through a sternotomy. Finally, the hybrid procedure showed significantly reduced transcardiac gradients of markers of coagulation, myocardial injury, and inflammation and a trend toward significant improvement in target-vessel patency.

CONCLUSIONS

Perhaps because of reduced myocardial injury, inflammation, and activation of coagulation, patients undergoing the hybrid procedure had better perioperative outcomes and satisfaction, with excellent patency at 1 year's follow-up. These promising preliminary findings warrant further investigation of this procedure.

Myocardial perfusion imaging evidence of functionally complete revascularization by minimally invasive direct coronary artery bypass in 2-vessel coronary artery disease

BACKGROUND

Whether patency of a second diseased vessel still impacts myocardial perfusion when complete revascularization of the left anterior descending coronary artery (LAD) territory has been achieved is currently undetermined. In patients with 2-vessel coronary artery disease and complex LAD lesions, we evaluated the impact of single LAD or integrated revascularization on single photon emission computed tomography-assessed reversible myocardial ischemia.

METHODS AND RESULTS

Thirty-five candidates for revascularization with double-vessel disease including the LAD and a preoperative stress single photon emission computed tomography study were studied. Revascularization was performed by minimally invasive direct coronary artery bypass (MIDCAB) alone (n = 15) or by an integrated procedure with second-vessel angioplasty, either soon after surgery (n = 13) or at 2 months (n = 7), according to the extent of reversible perfusion defects in the second vessel territory. At 1 year, the total ischemic area decreased from 9.3 +/- 5.1 to 0.8 +/- 1.5 in MIDCAB-only patients and from 8.2 +/- 4.9 to 1.6 +/- 2.9 in the integrated group (P = .87 for treatment and P < .001 for time). The ischemic area in the second vessel territory similarly decreased in both groups (P = .81 for treatment and P < .001 for time).

CONCLUSIONS

In 2-vessel coronary artery disease involving the LAD, MIDCAB alone achieves, in a substantial proportion of patients, functionally complete revascularization even in the nonrevascularized second vessel territory.

Cardiac protection by volatile anaesthetics

BACKGROUND AND OBJECTIVES

To evaluate the effects of total intravenous anaesthesia vs. volatile anaesthesia on cardiac troponin release in coronary artery bypass grafting with cardiopulmonary bypass, we performed a multicentre randomized controlled study to compare postoperative cardiac troponin release in patients receiving two different anaesthesia plans.

METHODS

We randomly assigned 75 patients to propofol (intravenous anaesthetic) and 75 patients to desflurane (volatile anaesthetic) in addition to an opiate-based anaesthesia for coronary artery bypass grafting. Peak postoperative troponin I release was measured as a marker of myocardial necrosis.

RESULTS

There was a significant (P < 0.001) difference in the postoperative median (25th-75th percentiles) peak of troponin I in patients receiving propofol 5,5 (2,3-9,5) ng dL(-1) when compared to patients receiving desflurane 2,5 (1,1-5,3) ng dL(-1). The median (interquartile) troponin I area under the curve analysis confirmed the results: 68 (30.5-104.8) vs. 36.3 (17.9-86.6) h ng dL(-1) (P = 0.002). Patients receiving volatile anaesthetics had reduced need for postoperative inotropic support (24/75, 32.0% vs. 31/75, 41.3%, P = 0.04), and tends toward a reduction in number of Q-wave myocardial infarction, time on mechanical ventilation, intensive care unit and overall hospital stay.

CONCLUSIONS

Myocardial damage measured by cardiac troponin release could be reduced by volatile anaesthetics in coronary artery bypass surgery.

Same-Day Combined Percutaneous Coronary Intervention and Coronary Artery Surgery

BACKGROUND

Either percutaneous coronary intervention (PCI) or coronary artery bypass grafting can be chosen for the treatment of multiple-vessel coronary artery disease. We report the results of a hybrid procedure performed on the same day, combining PCI of the right coronary artery and internal mammary artery bypass grafting of the left coronary artery, for the treatment of diffuse extensive lesions.

METHODS AND RESULTS

Since January 2000, 70 patients (53 male, mean age 68.5 +/- 10 years) underwent this hybrid revascularization combining primary right coronary artery PCI and, within the next 16 h, left coronary artery grafting with left and/or right internal mammary artery. Thirty-one patients (98%) were treated on the same day. At a mean follow-up of 33 months (range: 2-70 months), 68 patients (97%) were asymptomatic at the time of writing. Three adverse events were reported: 2 were PCI-related, due to failure to take ticlopidine, and 1 was surgery-related, resulting in the patient's death during hospitalization.

CONCLUSION

These preliminary results for a same-day combined procedure in patients with diffuse multivessel coronary artery disease are encouraging. This strategy optimizes revascularization when patients are unstable or present very severe coronary lesions, which requiring rapid treatment and are not ideally suitable for PCI management alone.

Pacing in adults with congenital heart disease

Adults with congenital heart disease constitute one of the fastest growing populations in cardiology. Pacing is an integral part of their therapy and may reduce their morbidity and mortality significantly. The current generation of pacemakers is more sophisticated and complex, and they are being utilized for indications other than conduction abnormalities, such as termination of tachycardia and improvement of heart failure. The complex anatomy and history of multiple previous surgeries in adults with congenital heart disease, however, pose many limitations and technical challenges related to the placement of a pacemaker. Unique and innovative approaches to endocardial lead placement and improved epicardial leads is making pacemaker implantation more feasible in these patients.

Endocardial Pacing After Fontan-Type Procedures

BACKGROUND

Sinus node dysfunction is a frequent complication of Fontan-type procedure. Epicardial pacing is considered as the standard treatment for these patients.

METHODS AND RESULTS

We evaluated an endocardial approach in seven patients using a 4.1 French bipolar lumenless lead (SelectSecure) that is positioned through a steerable guiding catheter. Either a purely transvenous or an open transatrial approach can be used for lead placement. The smallest child weighed 12 kg. Individual anatomy was assessed preimplantation using magnetic resonance imaging and injection of radiographic contrast agent through the guiding catheter. A pullback pressure recording was used to confirm unimpaired blood flow into the pulmonary artery. Five of our seven patients underwent de novo transvenous atrial lead implantation for AAIR pacing. In the remaining two patients, both atrial and ventricular leads were inserted. One patient with an intraatrial tunnel underwent transvenous-lead placement. The remaining patient with an extracardiac conduit received atrial and ventricular leads implanted through a guiding catheter inserted through an atriotomy. The postoperative management included short- or long-term oral anticoagulation.

CONCLUSIONS

Transvenous endocardial lead implantation avoids the problem of increasing capture thresholds typically observed with epicardial leads. Due to its high tensile strength and lumenless design, the isodiametric lead is expected to remain extractable for an extended period of time.

Endocardial Atrial Pacing Lead Implantation and Midterm Follow-Up in Young Patients with Sinus Node Dysfunction After the Fontan Procedure

The purpose of the study was to investigate the results of endocardial lead implantation, lead performance, and follow-up in young patients after the Fontan procedure. A retrospective study was conducted with patients who had endocardial atrial pacing for SND and intact AVN function after Fontan from two pediatric centers. Patient demographics, pacing, and sensing data of endocardial atrial leads were analyzed at the time of pacemaker implantation and follow-up visits. Fifteen patients (weight 42.6 +/- 35 kg) had transvenous endocardial atrial lead implantation at an average age of 11.4 +/- 6.5 years. Active-fixation leads were used in all patients and steroid elution was present in 12 (80%) patients. Adequate P wave sensing was obtained in patients with sinus rhythm (n = 10); the remaining four patients had junctional rhythm without measurable P waves. Lead failure was not observed in any patient during the follow-up period of 2.9 +/- 2.1 years. The energy threshold at implantation was 1.46 +/- 1.5 microJ, 1.54 +/- 0.75 microJ at 3 months, 0.62 +/- 0.45 microJ at 1 year, 0.72 +/- 0.65 microJ at 2 years, 0.75 +/- 0.55 microJ at 3 years, and 0.8 +/- 0.85 microJ at 5 years postimplant. The lead impedance was 648 +/- 298 omega at implantation, 714 +/- 163 omega at 3 months, 744 +/- 195 omega at 1 year, 734 +/- 198 omega at 2 years, 800 +/- 142 omega at 3 years and 830 +/- 200 omega 5 years postimplant. Anticoagulation therapy (aspirin n = 5, warfarin n = 8) was continued by 13 patients. Complications consisted of a pneumothorax at implantation and a transient ischemic attack in one patient 4 years after pacemaker implant. Endocardial atrial leads offer low energy thresholds and can be implanted relatively safely in Fontan patients.

Les facteurs cliniques et opératoires associés à la mortalité hospitalière après chirurgie d’une sténose du tronc commun de l’artère coronaire gauche

Stenosis of left main coronary artery (LMCA) is a common finding on coronary angiographies (7 to 10%). Mortality is very high for conservative therapy in comparison with surgery, which provides very good long-term outcome and is accepted as the standard therapy of this condition. Over the last few years, percutaneous coronary intervention (PCI) has become a new alternative in selected patients.

AIM OF THE STUDY

To assess in hospital mortality in subjects referred to our surgical unit for coronary artery bypass grafting (CABG) and to identify the main clinical and surgical determinants of in-hospital mortality.

METHODS

Two year retrospective analysis (1998-1999) of in-hospital mortality and morbidity of patients having left main stenosis referred for CABG.

RESULTS

Among a group of 1443 patients operated for coronary heart disease, LMCA stenosis was found in 330 patients (22.9%). The mean age was 63 +/- 8.6 years. Elective surgery was done in 173 patients (52.4%), and acute operation (i.e. urgent, emergent or desperate) in 157 patients (47.6%). The total in-hospital mortality was 4.2% (14/330). Elective surgery in-hospital mortality was 1.7% (3/173) and urgent surgery in-hospital mortality was 7% (11/157). The main risk factors of in-hospital mortality were age > 68 years, low ejection fraction (LVEF<0.4), history of myocardial infarction, gender (female) and urgency of the operation.

CONCLUSION

The proportion of patients undergoing CABG for left main stenosis is relatively high in our center and their mortality is quite low especially for elective operations. As the mortality of patients treated by PCI for LMCA stenosis is similar to surgery in high-risk patients, we postulate that this approach can be a real alternative treatment for such patients. Because of its potential benefit, combined revascularisation is also an alternative that should be considered in some cases. Furthermore, as a new generation of coated stents has emerged in the treatment of restenosis after PCI, we hypothesize that this method can in the near future be accepted as equivalent to surgery. However several randomized clinical trials must first be conduced prove this point.

Detecting and diagnosing arrhythmias in adults with congenital heart disease

Arrhythmias are a major cause of morbidity and mortality in adults with congenital heart disease; they can range from occult asymptomatic sinus node disease to sudden death. Detecting and diagnosing these arrhythmias presents a challenge when caring for these patients. A high index of suspicion is necessary, as well as a thorough understanding of the underlying heart defect and subsequent surgical interventions. A careful history, noninvasive evaluation, and in some cases invasive testing are all necessary to determine arrhythmias in this population.

Hibernation, Stunning, and Preconditioning: Historical Perspective, Current Concepts, Clinical Applications, and Future Implications

Despite considerable advances, coronary artery disease is the leading cause of morbidity and mortality in the Western world. The development of effective therapeutic strategies for protecting the myocardium from ischemia would have major impact on patients with coronary artery disease. It is now accepted that patients with coronary artery disease can experience prolonged regional ischemic dysfunction that does not necessarily arise from irreversible tissue damage, and to some extent, can be reversed by restoration of blood flow. The initial stages of dysfunction are probably caused by chronic stunning that can be reversed after revascularization, resulting in rapid and complete functional recovery. On the other hand, the more advanced stages of dysfunction likely correspond to chronic hibernation. After revascularization, functional recovery will probably be quite delayed and mostly incomplete. Over the past decade, the possibility that an innate mechanism of myocardial protection might be inducible in the human heart has generated considerable excitement. In the last two decades, there was phenomenal growth in the understanding of the mechanism known as ischemic preconditioning that is responsible for the innate myocardial protection. Continued research and progress in this area may soon lead to the availability of preconditioning-mimetic treatments. The current concepts, mechanisms, and potential clinical applications of myocardial hibernation, stunning, and ischemic preconditioning are reviewed.

Impact of preoperative renal dysfunction on cardiac surgery results

Results of cardiac surgery were analyzed using a database that included plasma creatinine levels in 2,214 patients, of whom 507 had preoperative renal dysfunction (creatinine clearance < 0.9 mL x s(-1) x m(-2)). Logistic regression and propensity score analyses found preoperative renal dysfunction to be an independent predictor of morbidity and mortality. Plotting preoperative creatinine clearance against morbidity and mortality revealed an exponential increase in morbidity and mortality when preoperative creatinine clearance was < 0.84 mL x s(-1) x m(-2). Patients were stratified for age, operative procedure, and comorbidity. In all stratified groups, preoperative creatinine clearance < 0.84 mL x s(-1) x m(-2) was associated with similar exponential increases in morbidity and mortality. In patients with preoperative renal dysfunction, elevated plasma creatinine levels persevered for 6 months postoperatively. Dialysis beyond postoperative day 10 was required in < 2% of patients with preoperative plasma creatinine of 160-200 micro mol x L(-1) and in 5% in those with creatinine > 200 micro mol x L(-1) (p < 0.05). Actuarial survival was significantly reduced (< 90% at 18 months postoperatively) in patients with preoperative renal dysfunction.

DDD pacemaker implantation after Fontan-type operations

Bradyarrhythmias developing after Fontan-type operations impair the function of the univentricular heart causing fatigue, headaches, ascites, and protein-losing enteropathy (PLE). Transvenous inaccessibility, requiring epicardial implantation, accounts for the reluctance to implant a pacemaker (PM). Between 1997 and 2000, 24 patients (mean age 9.5 years, range 6 months to 19 years) with Fontan-type operations received DDD pacing systems with atrial steroid-eluting stitch-on electrodes (mean capture threshold 1.9 V/0.5 ms, range 0.4-3.5 V) and ventricular screw-in electrodes (mean capture threshold 1.7 V/0.5 ms, range 0.1-3 V). The systems were implanted at the time of conversion from atrio- to cavopulmonary connections in 5 patients, at the time of a total cavopulmonary Fontan operation in 6, and 1-50 months thereafter (mean = 18) in 13 patients. A right ventricular anatomy was present in 13 (54%) of 24 of PM recipients, versus 35% of the overall population. After a mean follow-up of 3.5 years, the PM were functioning in DDD mode in 23 of the 24 patients. Length of hospital stay in the ten patients who underwent repeat sternotomy was 5 days, without procedure related complications. In three children a repeat sternotomy was avoided by implanting the atrial electrodes during the Fontan operation. All patients improved clinically, including resolution of PLE in four patients. Bradyarrhythmias may lead to significant morbidity after Fontan-type operations. Electrophysiological evaluation is advised at follow-up. The indication for implantation of a DDD pacemaker system should be liberal. Placing atrial electrodes during the Fontan operation, especially in the presence of a right ventricular anatomy, avoids repeat sternotomy.

The hybrid approach to coronary artery revascularization: minimally invasive direct coronary artery bypass with percutaneous coronary intervention

In the past decade, new developments in cardiology and cardiac surgery have begun to offer patients a variety of new, less invasive options for the treatment of coronary artery disease. One such option is the hybrid approach to coronary artery revascularization. This combines minimally invasive direct coronary artery bypass surgery (MIDCAB) of the left anterior descending artery (LAD) with percutaneous coronary intervention (PCI) of the remaining diseased coronary arteries. This approach, as an alternative to conventional coronary artery bypass surgery, retains the benefit of internal mammary artery bypass to the LAD, accomplished with a minimally invasive technique, substitutes PCI for saphenous vein grafts as treatment for low-grade lesions of other coronary arteries, and may provide a maximally beneficial outcome for many patients. Preliminary outcomes of patients receiving the hybrid approach have been strikingly positive. This report highlights the rationale for the development of this procedure, patient selection, results, and future applications of this emerging method of treating coronary artery disease.

Redo off-pump coronary artery bypass grafting for high risk hemodialysis patients

BACKGROUND

The number of reoperative (redo) coronary artery bypass grafting (CABG) for patients with long-term hemodialysis has been increasing. Off-pump CABG (OPCAB) may decrease risks associated with redo CABG.

METHODS

Two patients on chronic hemodialysis with calcification of the ascending aorta underwent redo double coronary OPCAB for the left anterior descending artery (LAD) and the posterior descending artery (PDA) via median sternotomy. The LAD was bypassed with the left internal thoracic artery (LITA). The PDA was exposed with minimum dissection and bypassed with a composite graft of the right internal thoracic artery (RITA) and the saphenous vein (SV).

RESULTS

Both patients made a quick recovery with no complications and one had postoperative angiography that showed the patent grafts. Both patients were free from angina pectoris at follow-up of 6 months and 3 months, respectively.

CONCLUSION

Redo OPCAB of the LAD and PDA can be performed with minimal dissection via median sternotomy using the LITA and a composite graft of the RITA and SV.

Coronary hybrid revascularization from January 1997 to January 2001: a clinical follow-up

BACKGROUND

Hybrid revascularization (HyR), combining minimally invasive left internal mammary artery (LIMA) bypass grafting to the left anterior descending coronary artery (LAD) and catheter interventional treatment of the remaining coronary lesions, avoids the disadvantages associated with cardiopulmonary bypass (CPB). We investigated the clinical follow-up of 57 patients with multivessel disease undergoing this procedure in the last 4 years.

METHODS

Between January 1997 and January 2001, 57 consecutive patients (41 men and 16 women, aged 65.7 +/- 7.9 years) with coronary artery disease (two-vessel, n = 34; three-vessel, n = 23) were treated with off-pump LIMA-to-LAD bypass combined with balloon angioplasty and stenting of the remaining significantly obstructed (> 50%) coronary vessels. Clinical follow-up data included a early postoperative and a 6-month control angiography and a patient interview in January 2001.

RESULTS

All patients underwent LIMA-to-LAD bypass-grafting and balloon angioplasty in 72 coronary lesions without procedural-related complications. However, one early LIMA bypass occlusion was documented during coronary angiography. Postoperatively no deterioration of preexistent organ dysfunction was observed in any patient. The mean follow-up was 100.7 +/- 37.9 weeks in 55 of 57 patients (97%). Control angiography 6 months after HyR (n = 34) revealed a patent LIMA bypass in 33 patients and 8 in-stent restenoses (> 50%) in the coronary arteries that were treated interventionally by re-PTCA (n = 6) or by conventional CABG (n = 1). In 1 patient medical treatment resulted in significant reduction of angina so no further intervention was considered necessary. After HyR 1 patient died 18 months later of an intracerebral hemorrhage. All other patients are alive and doing well.

CONCLUSIONS

Our results indicate that in selected patients with multivessel disease including left main stem stenosis HyR is an effective and secure procedure with excellent early and good midterm results. Especially elderly patients with severe concomitant diseases appear to benefit from this approach by avoiding CPB.

L-arginine protects human heart cells from low-volume anoxia and reoxygenation

Protective effects of L-arginine were evaluated in a human ventricular heart cell model of low-volume anoxia and reoxygenation independent of alternate cell types. Cell cultures were subjected to 90 min of low-volume anoxia and 30 min of reoxygenation. L-Arginine (0-5.0 mM) was administered during the preanoxic period or the reoxygenation phase. Nitric oxide (NO) production, NO synthase (NOS) activity, cGMP levels, and cellular injury were assessed. To evaluate the effects of the L-arginine on cell signaling, the effects of the NOS antagonist N(G)-nitro-L-arginine methyl ester, NO donor S-nitroso-N-acetyl-penicillamine, guanylate cyclase inhibitor methylene blue, cGMP analog 8-bromo-cGMP, and ATP-sensitive K+ channel antagonist glibenclamide were examined. Our data indicate that low-volume anoxia and reoxygenation increased NOS activity and facilitated the conversion of L-arginine to NO, which provided protection against cellular injury in a dose-dependent fashion. In addition, L-arginine cardioprotection was achieved by the activation of guanylate cyclase, leading to increased cGMP levels in human heart cells. This action involves a glibenclamide-sensitive, NO-cGMP-dependent pathway.

Extracellular ATP signaling and P2X nucleotide receptors in monolayers of primary human vascular endothelial cells

ATP and its metabolites regulate vascular tone; however, the sources of the ATP released in vascular beds are ill defined. As such, we tested the hypothesis that all limbs of an extracellular purinergic signaling system are present in vascular endothelial cells: ATP release, ATP receptors, and ATP receptor-triggered signal transduction. Primary cultures of human endothelial cells derived from multiple blood vessels were grown as monolayers and studied using a bioluminescence detection assay for ATP released into the medium. ATP is released constitutively and exclusively across the apical membrane under basal conditions. Hypotonic challenge or the calcium agonists ionomycin and thapsigargin stimulate ATP release in a reversible and regulated manner. To assess expression of P2X purinergic receptor channel subtypes (P2XRs), we performed degenerate RT-PCR, sequencing of the degenerate P2XR product, and immunoblotting with P2XR subtype-specific antibodies. Results revealed that P2X(4) and P2X(5) are expressed abundantly by endothelial cell primary cultures derived from multiple blood vessels. Together, these results suggest that components of an autocrine purinergic signaling loop exist in the endothelial cell microvasculature that may allow for "self-regulation" of endothelial cell function and modulation of vascular tone.

Combination of minimally invasive coronary bypass and percutaneous transluminal coronary angioplasty in the treatment of double-vessel coronary disease: Two-year follow-up of a new hybrid procedure compared with "on-pump" double bypass grafting

OBJECTIVE

Percutaneous transluminal coronary angioplasty (PTCA) or surgery can be chosen as first-line therapies in multiple-vessel coronary disease. A mammary-to-left anterior descending (LAD) graft is the most important statistical determinant of a favorable outcome after coronary artery bypass grafting (CABG) and can be performed with lower morbidity off pump through a minithoracotomy. PTCA and stenting of the "non-LAD" vessels compete with CABG in terms of patency rates. Our purpose was to compare a combination of minimally invasive direct coronary artery bypass (MIDCAB) and PTCA with double CABG as a treatment for double-vessel coronary artery disease involving the proximal LAD.

METHODS

Two matched groups of 20 patients with double-vessel coronary disease undergoing either sequential MIDCAB and PTCA (group 1) or double CABG on cardiopulmonary bypass (group 2) were compared. Angiographic control, complications, hospital costs, quality of life, and 2-year follow-up of ischemia are reported.

RESULTS

All bypasses were patent at early control. Three adverse events were noted in group 1 and 17 in group 2. The hybrid-procedure group exhibited a shorter intensive care unit stay, fewer blood products transfused, less pain, better early quality of life, faster return to work, and similar cost. Three patients required a second PTCA in group 1, one of which for restenosis. At 2 years all the patients are asymptomatic with no residual ischemia.

CONCLUSIONS

We conclude from this pilot study that the hybrid procedure is feasible and appears to be a safe therapy for double-vessel coronary artery disease and that it appears to generate less perioperative morbidity than classic double CABG does. Therefore we believe that there is room to undertake prospective randomized studies on a larger-scale basis.

Pharmacologic treatment of the stunned myocardium: the concepts and the challenges

During the past two decades (i.e., since 1980), in excess of 1000 published papers have focused on the phenomenon of the 'stunned myocardium', with many of these studies seeking to identify mechanisms-based treatment strategies to attenuate post-ischemic contractile dysfunction. Early investigations focused largely on abrogating the deleterious effects of oxygen-derived free radicals and unfavorable alterations in calcium homeostasis, both considered to contribute significantly to the pathogenesis of the stunned myocardium. More recently, favorable results have also been obtained using a somewhat different paradigm: that is, attempting to capitalize on endogenous cardioprotective mediators, most notably adenosine, nitric oxide, and the ATP-sensitive potassium channel. Now that potential therapeutic candidates have been identified in the experimental laboratory, the as-yet unmet challenge is to translate this information into the design of effective pharmacologic therapies to treat myocardial stunning in the clinical arena.

Provisional stenting in small vessels

Based on the currently available data, the strategy of routine stent placement in unselected lesions located in small coronary arteries provides good immediate results but is still associated with a high incidence of in-stent restenosis. Randomized trials comparing elective stenting with balloon angioplasty have not provided the demonstration that routine stenting is the best strategy for percutaneous intervention in coronary arteries with a reference diameter smaller than 2.75-3.0 mm. This paper describes the rationale for provisional stenting in this clinical setting and reviews the role of quantitative coronary angiography, intracoronary ultrasound and intracoronary Doppler measurements in the identification of lesions that would benefit from adjunctive stent placement after balloon angioplasty and in guiding stent implantation.

An introduction to provisional stenting

Provisional or conditional stenting should be defined as the use of stents limited to those conditions and cases in which the operator, despite an aggressive balloon angioplasty technique with large balloons and high pressure, has been unable to obtain a result that ensures optimal chances of early and late patency. The paramount issue is how to discriminate the patients with optimal results after balloon angioplasty for whom additional stent implantation is unlikely to improve or may even worsen long-term outcome. The better results of elective stent implantation in the OPUS study suggest that visual assessment of the PTCA result is not sufficient to detect lesions with suboptimal lumen gain after PTCA. The addition of physiologic parameters (Doppler flow velocity measurements, fractional flow reserve) has improved the results of the provisional stent group, with the best outcome observed when complex lesions and multivessel treatment were included in these studies (FROST, DESTINI). Intravascular ultrasound, although more expensive and time-consuming, has the additional advantage to guide the dilatation strategy.

Integrated minimally invasive approaches for the treatment of atherosclerotic vascular diseases: Hybrid procedures

Patients may develop simultaneous symptoms of atherosclerotic vascular disease from different arterial beds. A concurrent minimally invasive approach to the management of these clinical situations may be an advantage over conventional surgical procedures. This study describes two separate case series of patients undergoing coronary/peripheral (n = 38) and peripheral/peripheral procedures (n = 10). Technical and clinical success was achieved in all patients. There were two periprocedural complications (retroperitoneal bleed and septicemia) in the coronary/peripheral series and no complications in the peripheral/peripheral series. We also present five case reports to illustrate the utility of hybrid procedures in various clinical settings. This study suggests that the use of simultaneous or sequential minimally invasive procedures appears to be a safe and feasible strategy for the treatment of patients with symptoms from more than one vascular bed. Cathet Cardiovasc Intervent 2001;52:154-161.

Coronary Surgery: off-pump and port access

Attempts to minimize the invasiveness of cardiac surgery have focused on decreasing access trauma and eliminating cardiopulmonary bypass. The initial procedures, minimally invasive direct coronary artery bypass (MIDCAB, limited access beating heart) and port access (limited access arrested heart), have become niche procedures. Off-pump coronary artery bypass (OPCAB, median sternotomy beating heart) presently accounts for approximately 15% of all coronary bypass operations performed in the United States. Morbidity and cost appear to be decreased with these procedures. Feasibility trials of endoscopic coronary bypass surgery using robotic devices are underway in many centers. It is anticipated that over the next 5 years the alternative approaches to conventional coronary artery bypass surgery will continue to grow as methods of coronary revascularization.

Elderly Patients with Acute Coronary Syndromes: Higher Risk and Greater Benefit from Antithrombotic and Interventional Therapies

In elderly patients with acute coronary syndromes, outcomes are poorer than in younger patients and, disappointingly, some therapies-including thrombolysis for ST elevation myocardial infarction-confer less benefit than in younger patients. In contrast, in unstable angina and non-ST elevation myocardial infarction, the elderly appear to derive greater relative and absolute benefit from the newer, more potent antithrombotic therapies. In both the Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-Wave Coronary Events and Thrombolysis in Myocardial Infarction 11B trials, the low molecular weight heparin enoxaparin, compared with unfractionated heparin, appeared to have greater relative and absolute benefit in patients aged 65 years and older, as compared with younger patients. For the glycoprotein IIb/IIIa inhibitors, an equivalent relative benefit has been observed, which translated into a greater absolute benefit in older vs. younger patients. Similarly, in the FRagmin and Fast Revascularisation during InStability in Coronary Artery Disease II trial, patients 65 years and older derived significantly greater benefit from an invasive than from a conservative strategy, whereas there was no difference in outcome by strategy in younger patients. A similar trend was observed in the Thrombolysis in Myocardial Infarction IIIB trial. Thus, in unstable angina and non-ST elevation myocardial infarction, elderly patients are at higher risk and appear to derive particular benefit from the more aggressive antithrombotic and interventional therapies. (c) 2000 by CVRR, Inc.

Economic outcome of off-pump coronary artery bypass surgery: a prospective randomized study

BACKGROUND

Emphasis on cost containment in coronary artery bypass surgery is becoming increasingly important in modern hospital management. The revival of interest in off-pump (beating heart) coronary artery bypass surgery may influence the economic outcome. This study examines these effects.

METHODS

Two hundred patients undergoing first-time coronary artery bypass surgery were prospectively randomized to either conventional cardiopulmonary bypass and cardioplegic arrest or off-pump surgery. Variable and fixed direct costs were obtained for each group during operative and postoperative care. The data were analyzed using parametric methods.

RESULTS

There was no difference between the groups with respect to pre- and intraoperative patient variables. Off-pump surgery was significantly less costly than conventional on-pump surgery with respect to operating materials, bed occupancy, and transfusion requirements (total mean cost per patient: on pump, $3,731.6+/-1,169.7 vs off-pump, $2,615.13+/-953.6; p < 0.001). Morbidity was significantly higher in the on-pump group, which was reflected in an increased cost.

CONCLUSIONS

Off-pump revascularization offers a safe, cost-effective alternative to conventional coronary revascularization with cardiopulmonary bypass and cardioplegic arrest.

Same-day combined coronary angioplasty and minimally invasive coronary surgery

Integrated myocardial revascularization combines the advantages of angioplasty, stenting, and minimally invasive surgery to revascularize patients with multivessel coronary artery disease without cardiopulmonary bypass. This pilot study showed that a new same-day management strategy, consisting of percutaneous coronary intervention followed immediately by minimally invasive surgery, was feasible and provided complete all-arterial revascularization with minimal surgical trauma, short hospital stay, and excellent early therapeutic result in 14 patients with multivessel coronary disease.

[Hybrid revascularization]

OBJECTIVE

To evaluate our initial experience in the combination of two less invasive procedures for myocardial revascularization, coronary artery bypass grafting without cardiopulmonary bypass and immediate posterior angioplasty, on untreated lesions (hybrid revascularization) as an alternative treatment to conventional surgery in selected patients.

MATERIAL AND METHODS

From october 1996 to September 1998, 19 patients received hybrid revascularization. The mean age was 64 (47-76). Two patients underwent urgent surgery. Two patients had left main coronary disease, and 9 three-vessel disease. In general, we considered this procedure for patients with high-risk factors for cardiopulmonary bypass and two or more vessel disease. The internal mammary artery was connected to the left anterior descending artery in all 19 patients. All patients were moved to the hemodynamic ward immediately after surgery in 7 cases and before 48 h in the rest, 24 angioplasties were performed. A mean of 2.6 vessels per patient were revascularized and revascularization was complete in 15 patients (79%).

RESULTS

One patient had perioperative myocardial infarction. There was no hospital mortality. Length of stay in the intensive care unit was 44 h (IQR = 49) and global postoperative stay was 8 days (IQR = 3.5). In the postoperative angiographic study, before the angioplasty, 95% of mammary arteries (CI 95% 74-100%) and 100% of saphenous grafts (CI 95% 59-100%) were patent.

CONCLUSIONS

Combined revascularization allows almost complete revascularization, avoiding complications of cardiopulmonary bypass and minimizing surgical aggression. At the same time, it secures the graft of internal mammary artery to left anterior descending artery.

Integrated myocardial revascularization

The integration of minimally invasive coronary artery bypass grafting with catheter-based interventions is being practiced with increasing frequency both in the standard and high risk patient populations. The procedures can be staged on different days or done concurrently in either an operative cathlab or an operating room with imaging capabilities. The new clinical issues raised with these new approaches are reviewed for practitioners considering adopting this new treatment strategy.

Polarization and myocardial protection

Heart surgery or transplantation generally involve global ischemia, and techniques have been developed to protect the myocardium from ischemic and reperfusion injury. Hyperkalemic cardioplegia has been the gold standard for myocardial protection for years, but patients undergoing surgery almost invariably have some postoperative dysfunction. One factor may be the depolarizing nature of hyperkalemia, which results in continuing transmembrane fluxes and metabolism, even during hypothermic ischemia. A potentially beneficial alternative to hyperkalemic (depolarizing) cardioplegia is arrest in a "hyperpolarized" or "polarized" state, which maintains the myocardial membrane potential at or near the resting potential. This should minimize transmembrane fluxes and metabolic demand and improve myocardial protection. These alternative concepts have recently been investigated by using adenosine and potassium-channel openers (which are thought to induce hyperpolarized arrest) or the sodium-channel blocker tetrodotoxin (which induces polarized arrest), and results have been beneficial compared with the results of hyperkalemia. Additional studies are needed before experimental promise can become clinical reality.