Talal Al-Atassi

Successful treatment of heart failure due to acute transplant rejection with the Impella LP 5.0.

Cardiogenic shock resulting from transplant rejection is a serious complication with high mortality and morbidity. Often resistant to maximal medical therapy, this condition frequently requires mechanical circulatory support until recovery or retransplantation. We present a 52-year-old patient with multiorgan failure secondary to acute graft rejection after orthotopic heart transplantation. Maximal medical therapy was not successful, and the patient was bridged to recovery with an Impella LP 5.0 (Abiomed Inc, Danvers, MA) left ventricular assist device (LVAD). The relative merits of this therapeutic approach are outlined and discussed. The patient was discharged 3 weeks after LVAD removal and remains clinically stable.

The effect of using microplegia on perioperative morbidity and mortality in elderly patients undergoing cardiac surgery

Old age is a significant risk factor for perioperative morbidity and mortality following cardiac surgery and optimal myocardial protection strategy should be sought in this group of patients. We, therefore, reviewed the data on 295 consecutive patients older than 75 years who underwent any cardiac surgical procedure. Microplegia was used in 144 patients compared to 151 patients who had the standard 4:1 blood cardioplegia. Logistic regression analysis was used for propensity matching to balance the differences between the two groups. The microplegia group included more females and sicker patients as indicated by higher Parsonnet scores. There were differences in the pump time, aortic cross-clamp time, procedure type and surgeons between the two groups. These differences were balanced using the propensity matching. In-hospital mortality, acute renal injury and confusion were higher in the microplegia group (17%, 34%, 35%, respectively) compared to the standard 4:1 cardioplegia group (9%, 23%, 24%, respectively) (P=0.04, 0.04, 0.04, respectively). These differences were not statistically significant after propensity matching. These results demonstrate that the use of microplegia is safe in patients older than 75 years who are undergoing cardiac surgery and results in similar in-hospital morbidity and mortality to the standard 4:1 blood cardioplegia.

Impact of clopidogrel plus aspirin versus aspirin alone on the progression of native coronary artery disease after bypass surgery: analysis from the Clopidogrel After Surgery for Coronary Artery DiseasE (CASCADE) randomized trial.

Background— The effects of dual antiplatelet therapy with aspirin and clopidogrel on the progression of native coronary artery disease after coronary artery bypass grafting are unknown. Methods and Results— In the Clopidogrel After Surgery for Coronary Artery DiseasE (CASCADE) trial, a total of 113 patients were randomized to receive aspirin plus clopidogrel or aspirin plus placebo for 1 year after coronary artery bypass grafting. In this secondary analysis, the 92 patients who underwent preoperative and 1-year postoperative angiograms at 2 centers had each of their coronary stenoses graded serially by using 6 thresholds (grade 0 [0%–24%], grade 1 [25%–37%], grade 2 [38%–62%], grade 3 [63%–82%], grade 4 [83%–98%], and grade 5 [99%–100%]). We compared the incidence and degree of evolving coronary artery disease between the 2 treatment groups. A total of 543 preoperative stenoses and occlusions were quantified and followed. At 1-year postoperatively, there were 103 evolving (94 worsened, 9 improved) and 22 new lesions. The right coronary artery territory and sites proximal to a graft were more commonly associated with worsening coronary artery disease (P⩽0.02). There were no differences in clinical events between treatment groups, and the proportion of patients with evolving or new lesions was also similar (70% versus 74%, aspirin–clopidogrel versus aspirin–placebo, respectively; P=0.8). However, in evolving or new lesions, the mean grade change (1.1±1.0 versus 1.6±1.1, respectively; P=0.01) and the proportion of new occlusions (7% versus 22%; P=0.02) were lower in the aspirin–clopidogrel group. Conclusions— The addition of clopidogrel to aspirin correlates with less worsening of native coronary artery disease 1 year after coronary artery bypass grafting. These findings may help guide post–coronary artery bypass grafting antiplatelet therapy. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00228423.

Finding the ideal biomaterial for aortic valve repair with ex vivo porcine left heart simulator and finite element modeling

OBJECTIVES Aortic valve (AV) repair (AVr) has become an attractive alternative to AV replacement for the correction of aortic insufficiency; however, little clinical evidence exists in determining which biomaterial at AVr would be optimal. Cusp replacement in AVr has been associated with increased long-term AVr failure. We measured the hemodynamic and biomaterial properties using an ex vivo porcine AVr model with clinically relevant biomaterials and generated a finite element model to ascertain which materials would be best suited for valve repair. METHODS Porcine aortic roots with intact AVs were placed in a left heart simulator mounted with a high-speed camera for baseline valve assessment. The noncoronary cusp was excised and replaced with autologous porcine pericardium, glutaraldehyde-fixed bovine pericardial patch (Synovis), extracelluar matrix scaffold (CorMatrix), or collagen-impregnated Dacron (Hemashield). The hemodynamic parameters were measured for a range of cardiac outputs (2.5-6.5 L/min) after repair. The biomaterial properties and St Jude Medical pericardial patch were determined using pressurization experiments. Finite element models of the AV and root complex were constructed to determine the hemodynamic characteristics and leaflet stresses. RESULTS The geometric orifice areas after repair were significantly reduced in the Hemashield (P<.05) and CorMatrix (P=.0001) groups. Left ventricular work increased with increasing cardiac output (P=.001) in unrepaired valves, as expected, and was similar among all biomaterial groups. Finite element modeling of the biomaterials displayed differences in the percentage of changes in total Von Mises stress for both replaced (noncoronary cusp) and nonreplaced left and right cusps with the St Jude Medical pericardial patch (+4%, +24%) and autologous porcine pericardium (+5, +26%), with a lower percentage of changes than for the bovine pericardial patch (+12%, +27%), Hemashield (+30%, +9%), and CorMatrix (+13%, +32%). CONCLUSIONS The present study has shown that postrepair left ventricular work did not increase despite a decrease in geometric orifice areas in the Hemashield and CorMatrix groups. The autologous porcine pericardium and St Jude Medical pericardial patch had the closest profile to normal AVs; therefore, either biomaterial might be best suited. Finally, the increased stresses found in the bovine pericardial patch, Hemashield, and CorMatrix groups might, after prolonged tensile exposure, be associated with late repair failure.

Endovascular treatment for cerebral septic embolic stroke.

This case demonstrates an alternative approach to cerebral revascularization by performing both intravascular mechanical thrombectomy and local injection of thrombolytics that may reduce mortality, bleeding, and the diminished quality of life experienced by patients following an acute septic embolic stroke.

Cerebral Microembolization After Bioprosthetic Aortic Valve Replacement Comparison of Warfarin Plus Aspirin Versus Aspirin Only

Background— No human physiological data exists on whether aspirin only is as effective as warfarin plus aspirin in preventing cerebral microembolization in the early postoperative period after bioprosthetic aortic valve replacement (bAVR). Methods and Results— We prospectively enrolled 56 patients who had no other indication for oral anticoagulation, who underwent bAVR and received, in an open-label fashion, either daily warfarin (for INR 2.0–3.0) plus 81 mg of aspirin (n=28) or 325 mg of aspirin only (n=28). Cerebral microembolization was quantified at 4 hours (baseline) and at 1 month postoperatively, by recording 1-hour bilateral middle cerebral artery (MCA) microembolic signals (MES). Platelet-function analysis (PFA) of closure times (CT) on collagen was also used as a marker of platelet-dependent activation. Follow-up to 1 year was complete. Preoperative demographics and baseline platelet function were equivalent in both groups. There was no mortality, stroke, or transient ischemic attack at 1 year in either group. No significant differences were found in the proportion of patients with MES among those receiving warfarin plus aspirin versus aspirin only, at baseline (68% versus 82%, respectively; P=0.4) and at 1 month (46% versus 43%; P=1.0) after bAVR. The total MES and PFA were also equivalent between groups, at baseline and follow-up. Conclusions— Early after bAVR, the effects of these 2 antithrombotic regimens on cerebral microembolization and platelet function are equivalent. These data bring new mechanistic support to the premise that aspirin only may safely be used early after bAVR in patients who have no other indication for oral anticoagulation.

Preclinical Evaluation of Biopolymer-Delivered Circulating Angiogenic Cells in a Swine Model of Hibernating Myocardium

Background—Vasculogenic cell–based therapy combined with tissue engineering is a promising revascularization approach targeted at patients with advanced coronary artery disease, many of whom exhibit myocardial hibernation. However, to date, no experimental data have been available in this context; we therefore examined the biopolymer-supported delivery of circulating angiogenic cells using a clinically relevant swine model of hibernating myocardium. Methods and Results—Twenty-five swine underwent placement of an ameroid constrictor on the left circumflex artery. After 2 weeks, animals underwent echocardiography, rest and stress ammonia-positron emission tomography perfusion, and fluorodeoxyglucose positron emission tomography viability scans. The following week, swine were randomized to receive intramyocardial injections of PBS control (n=10), circulating angiogenic cells (n=8), or circulating angiogenic cells+collagen-based matrix (n=7). The imaging protocol was repeated after 7 weeks. Baseline positron emission tomography myocardial blood flow and myocardial flow reserve were reduced in the left circumflex artery territory (both P<0.001), and hibernation (mismatch) was observed. At follow-up, stress myocardial blood flow had increased (P⩽0.01) and hibernation decreased (P<0.01) in the cells+matrix group only. Microsphere-measured myocardial blood flow validated the perfusion results. Arteriole density and wall motion abnormalities improved in the cells+matrix group. There was also a strong trend toward an improvement in ejection fraction (P=0.07). Conclusions—In this preclinical swine model of ischemic and hibernating myocardium, the combined delivery of circulating angiogenic cells and a collagen-based matrix restored perfusion, reduced hibernation, and improved myocardial wall motion.

An update on mechanical circulatory support for heart failure therapy.

Purpose of review This article aims to review contemporary studies that utilized mechanical circulatory support (MCS) in the treatment of heart failure and to elaborate on prospective mechanical alternatives. Recent findings There is a growing need for a well-tolerated, durable and effective MCS option in patients with refractory heart failure. In previous years, the primary indication for MCS therapy supported bridge to transplantation. These early left ventricular assist devices (LVADs) suffered significant adverse events, thereby limiting their prolonged use. With the introduction of newer continuous flow LVADs, with lower morbidity, neurological events, pump failure and the expanded indication use (i.e. destination therapy), the overall number of implanted patients has grown. Summary There has been a dramatic advancement of durability found in the second and third-generation, continuous flow LVADs, along with improved survival rates in patients receiving these devices for destination therapy. MCS may soon become the treatment option of choice in refractory heart failure patients, especially with further evolution of less invasive approaches, smaller designs, and energy sources.

Treatment of the Chronic Type B Aortic Dissection: The Pro-endovascular Argument

Although thoracic endovascular aortic repair (TEVAR) is the standard of care in acute complicated type B dissections, its role in chronic type B dissections remains controversial. This controversy stems from anatomical differences between acute and chronic dissections, such as a thicker intimal clap and improved results in descending aortic replacement. However, despite these important differences, there has been accumulating evidence on the safety and efficacy of TEVAR in chronic type B aortic dissections, especially when considering the alternative of open surgical repair, which is associated with significantly higher morbidity and in many hands also higher mortality. Herein, we discuss the evidence in the literature highlighting TEVARs safety and efficacy in this setting.

Atrial fibrillation therapies: lest we forget surgery.

Atrial fibrillation (AF) is a disease that causes a significant burden in a patients life. It is a known risk factor for heart failure, stroke, and premature death. The classic therapeutic strategies include rate control, rhythm control, and prevention of stroke. Pharmacological rhythm control with antiarrhythmic drugs can only be achieved 50% of the time while simultaneously subjecting patients to deleterious adverse reactions. With recent advances in catheter ablation procedures, rhythm control can be safely attained anywhere from 57%-80% of the time, depending on the number of repeat catheter ablation procedures that are performed and concomitant use of antiarrhythmic drugs. The Cox-Maze procedure is a technically challenging cut-and-sew atrial lesion set with associated morbidity, yet is still considered the gold standard for rhythm control. Fortunately, this procedure has been modified in efforts to improve the safety profile (shorter cross clamp and cardiopulmonary bypass time), to simplify lesion set creation with newer energy sources, and to perform this operation in a minimally invasive setting. Minimally invasive surgical AF ablation techniques have excellent safety profiles and can achieve rhythm control in up to 90% of patients. In contrast, patients undergoing open heart surgery can undergo either concomitant endocardial or epicardial AF ablation procedures without jeopardizing the surgery along with success rates from 60% to 88%. Thus, there has been an increase in current surgical options for treating AF because of novel approaches and energy sources which yield effective long-term results in patient care and minimize perioperative complications and thereby optimize the risk/benefit ratio profile.