S. Pecha

Cardiac repair in guinea pigs with human engineered heart tissue from induced pluripotent stem cells

Human engineered heart tissue derived from induced pluripotent stem cells improves cardiac function in guinea pigs. A patch for a broken heart A heart attack destroys cardiac muscle, resulting in a fibrotic scar. Weinberger et al. created a living patch for injured hearts using endothelial and cardiac cells grown from human induced pluripotent stem cells. These three-dimensional strips were placed over injured areas of guinea pig hearts; 28 days later, the injured area was partly remuscularized, and the heart pumped ~30% better than just after the injury. The grafts also contained new blood vessels and, in some cases, were electrically coupled to the healthy parts of the heart. These human heart patches may one day help patients recover cardiac function after a heart attack. Myocardial injury results in a loss of contractile tissue mass that, in the absence of efficient regeneration, is essentially irreversible. Transplantation of human pluripotent stem cell–derived cardiomyocytes has beneficial but variable effects. We created human engineered heart tissue (hEHT) strips from human induced pluripotent stem cell (hiPSC)–derived cardiomyocytes and hiPSC-derived endothelial cells. The hEHTs were transplanted onto large defects (22% of the left ventricular wall, 35% decline in left ventricular function) of guinea pig hearts 7 days after cryoinjury, and the results were compared with those obtained with human endothelial cell patches (hEETs) or cell-free patches. Twenty-eight days after transplantation, the hearts repaired with hEHT strips exhibited, within the scar, human heart muscle grafts, which had remuscularized 12% of the infarct area. These grafts showed cardiomyocyte proliferation, vascularization, and evidence for electrical coupling to the intact heart tissue in a subset of engrafted hearts. hEHT strips improved left ventricular function by 31% compared to that before implantation, whereas the hEET or cell-free patches had no effect. Together, our study demonstrates that three-dimensional human heart muscle constructs can repair the injured heart.

Event recorder monitoring to compare the efficacy of a left versus biatrial lesion set in patients undergoing concomitant surgical ablation for atrial fibrillation.

OBJECTIVES Various lesion sets and subsequent success rates have been reported in patients receiving concomitant surgical ablation for atrial fibrillation. However, most of these results have been obtained by discontinuous monitoring. We report results using continuous event recorder rhythm monitoring to compare more accurately the efficacy of a left versus biatrial lesion set to treat patients with persistent atrial fibrillation. METHODS Between July 2008 and December 2011, 66 patients with persistent or long-standing persistent atrial fibrillation underwent concomitant surgical atrial fibrillation ablation with a biatrial lesion set and subcutaneous event recorder implantation. The results and outcomes were compared with a propensity score-matched cohort of 66 patients with a left atrial lesion set and event recorder implantation. Event recorder interrogation was performed at 3, 6, and 12 months follow-up. RESULTS The mean patient age was 70.2±7.4 years, and 70.3% were male. No major ablation-related complications occurred. One-year survival was 94.8% with no statistically significant differences between the 2 groups. The overall rate of freedom from atrial fibrillation was 57.3% and 64.4% after 3 and 12 months follow-up, respectively. Three months postoperatively, patients in the biatrial group had a slightly higher rate of freedom from atrial fibrillation (63.6% vs 52.3% P=.22), but it did not reach statistical significance. At 12 months follow-up, a statistically significant higher rate of freedom from atrial fibrillation was observed in patients with a biatrial lesion set (74.4% vs 55.8%; P=.026). The mean atrial fibrillation burden in all patients was 15.1%±12.5% in the biatrial group and 21.2%±14.4% in the left atrial group 12 months postoperatively (P=.03). CONCLUSIONS Continuous rhythm monitoring by subcutaneous event recorder implantation was safe and feasible. In patients undergoing biatrial ablation, a statistically significant higher rate of freedom from atrial fibrillation was observed at 12 months follow-up.

Initial experience of pacemaker and implantable cardioverter defibrillator lead extraction with the new GlideLight 80 Hz laser sheaths

OBJECTIVES Laser lead extraction is a challenging procedure, especially in patients with old or multiple pacemaker (PM) or implantable cardioverter defibrillator (ICD) leads. The mechanical force is a leading cause of complications during the extraction procedure. Use of new laser sheaths, which deliver a rate of 80 pulses per second, may probably reduce intraoperative adverse events by reduction of extraction force. METHODS Between January 2012 and April 2013, 76 PM and ICD leads were treated in 38 patients using GlideLight 80 Hz laser sheaths. Indications for lead removals were pocket infection (42.1%), septicaemia or endocarditis (23.7%), lead dysfunction (31.6%) and upgrade from PM to ICD (2.6%). Data on procedural success rates, intra- and postoperative outcomes, as well as 30-day mortality were collected into a database and analysed retrospectively. RESULTS The mean patient age was 62.0 ± 17.7 years (range 18-83), and 73.7% were male. The mean time from initial lead implantation was 96.0 ± 58.3 months (range 24-288). Thirty-seven (48.7%) PM and 39 (51.3%) ICD leads had to be extracted. The mean procedural time was 68.3 ± 27.3 min (range 35-115). Seventy-two of 76 leads (94.8%) were completely removed, partial removal was achieved in 2 (2.6%) leads and a failure of extraction occurred in 2 (2.6%) leads. The overall complication rate was 5.2%, including one major (superior vena cava perforation) (2.6%) and one minor (pocket haematoma) (2.6%) complication. No death occurred during the 30-day follow-up. CONCLUSIONS The GlideLight 80 Hz laser sheath allows safe and effective removal of chronically implanted PM and ICD leads, combining high procedural success with low complication rates.

Efficacy of prophylactic intra-aortic balloon pump therapy in chronic heart failure patients undergoing cardiac surgery.

This study investigated the efficacy of prophylactic intraoperative intra-aortic balloon pump (IABP) usage in chronic heart failure patients with severely reduced left ventricular function undergoing elective cardiac surgery. Between January 2008 and December 2012, 107 patients with severely reduced left ventricular ejection fraction (LVEF <35%) received prophylactic intraoperative IABP implantation during open-heart surgery. Surgical procedures performed were isolated coronary artery bypass grafting (CABG) in 35 patients (32.7%), aortic valve replacement in 12 (11.2%), mitral valve repair or replacement in 15 (14.0%), combined valve and CABG procedures in 27 (25.2%), and other surgical procedures in 18 (16.8%). Results and outcomes were compared with those in a propensity score-matched cohort of 107 patients who underwent cardiac surgery without intraoperative IABP implantation. Matching criteria were age, gender, LVEF, and surgical procedure. Duration of intensive care unit (ICU) stay, duration of hospital stay, and 30-day mortality were markers of outcome. In the IABP group, mean patient age was 69.1 ± 13.7 years; 66.4% (70) were male. All IABPs were placed intraoperatively. Mean duration of IABP application time was 42.4 ± 8.7 h. IABP-related complications occurred in five patients (4.7%), including one case of inguinal bleeding, one case of mesenteric ischemia, and ischemia of the lower limb in three patients. No stroke or major bleeding occurred during IABP support. Mean durations of ICU and hospital stay were 3.38 ± 2.15 days and 7.69 ± 2.02 days, respectively, in the IABP group, and 4.20 ± 3.14 days and 8.57 ± 3.26 days in the control group, showing statistically significant reductions in duration of ICU and hospital stay in the IABP group (ICU stay, P = 0.036; hospital stay, P = 0.015). Thirty-day survival rates were 92.5 and 94.4% in the IABP and control group, respectively, showing no statistically significant difference (P = 0.75). IABP usage in chronic heart failure patients with severely reduced LVEF undergoing cardiac surgery was safe and resulted in shorter ICU and hospital stay but did not influence 7- and 30-day survival rates.

Uncommon cause of pulmonary hypertension

A 61-year-old male presented with intermittent palpitations and exertional dyspnea. Transthoracic echocardiography revealed a 5.7 × 4.5-cm mobile mass attached to the left atrial septum, and partially obstructing the mitral orifice (Figs. 1 and 2) and the left ventricular outflow tract (Fig. 3). The systolic pulmonary artery pressure was 108mmHg. The surgical procedure was performed via a right anterolateral mini-thoracotomy with femoral cannulation using an endoscopic (Aesculp, Einstein Vision, Tottlingen, Germany) technique. The mass was visualized via a posterior left atriotomy (Fig. 4) and was entirely removed during a 31-min cross clamp period (Fig. 5). The patient tolerated the procedure well. The histology demonstrated a benign myxoma with negative tumor margins (Fig. 6). A postoperative echocardiogram showed no residual mass, and the pulmonary artery systolic pressure was decreased to normal values (Fig.7).

Myocardial Tissue Engineering for Cardiac Repair

The number of patients with heart failure is increasing in the aging population. Heart transplantation remains the only curative treatment option for patients with end-stage heart failure. Because of an organ donor shortage, new organ-independent treatment options are necessary. Different approaches to cardiac repair therapies have been developed and optimized in recent years. One of these promising approaches is myocardial tissue engineering, which refers to the creation of 3-dimensional engineered heart tissue in vitro. This perspective provides an overview of different approaches to tissue engineering, including essentials to improve tissue quality and choice of ideal cell source, as well as an overview of in vitro and in vivo studies. Several hurdles that have to be overcome before clinical application of engineered heart tissue might become a realistic scenario are also addressed.

Successful extracorporeal membrane oxygenation weaning after cardiac resynchronization therapy device implantation in a patient with end-stage heart failure

We present the case of a 46-year old male with end-stage heart failure due to ethyltoxic cardiomyopathy. The patient did not meet the criteria for heart transplantation and declined left ventricular assist device implantation. We decided to conduct cardiac resynchronization therapy defibrillator (CRT-D) implantation. Under general anaesthesia for CRT-D implantation, cardiac function worsened. Due to deteriorating haemodynamics, CRT-D implantation was aborted and emergent veno-arterial extracorporeal membrane oxygenation (ECMO) implantation was performed. Subsequent weaning from ECMO was not possible. We decided to proceed with CRT-D implantation while still on ECMO support. With biventricular stimulation, cardiac function improved promptly and the patient could be weaned from ECMO the same day.

Laser lead extraction allows for safe and effective removal of single- and dual-coil implantable cardioverter defibrillator leads: A single-centre experience over 12 years

OBJECTIVES Lead extraction in patients with multiple or old leads of an implantable cardioverter defibrillator (ICD) is challenging. As adhesions are common at the side of the shock coils, we investigated success and procedural complication rates of laser lead extraction procedures in single- and dual-coil leads. METHODS Between January 2001 and June 2013, 41 single- and 145 dual-coil ICD leads were extracted from 171 patients using laser sheaths. Procedural data, success rates and complications were collected into a database and retrospectively analysed. RESULTS The mean patient age was 58.2 ± 16.1 years. The mean time from initial lead implantation to extraction was 50.3 ± 18.4 and 45.8 ± 14.5 months in the single- and dual-coil group, respectively (P = 0.1). In the single-coil group, complete procedural success was achieved in 36 of 37 (97.3%) cases, and clinical success in all cases (100.0%). In the dual-coil group, complete procedural success was seen in 131 out of 134 (97.8%) patients, and clinical success in 132 of 134 cases (98.5%). The transvenous extraction failed in 2 cases (1.5%). The overall complication rate was 2.7% in the single-coil group and 3.7% in the dual-coil group, respectively (P = 1.0). No deaths occurred during the 30-day follow-up. The mean laser treatment time was 1.8 ± 1.5 min for the single-coil group and 2.5 ± 1.2 min for dual-coil group (P = 0.002). CONCLUSIONS Laser lead extraction allows for safe and effective removal of ICD leads. Compared with single-coil leads, the extraction of dual-coil leads is associated with longer laser treatment times but without statistically significant differences in complications and procedural success rates.

Mechanically induced ventricular tachycardia by the HeartWare ventricular assist device.

Fulminant myocarditis can lead to acute left ventricular dilatation and cardiogenic shock from heart failure. If hemodynamic stabilization cannot be achieved with maximized medical therapy, mechanical circulatory support becomes necessary. We here report on a 40-year-old patient who underwent emergent left ventricular assist device (LVAD) implantation (HVAD, HeartWare) in cardiogenic shock level 1 (Interagency Registry for Mechanically Assisted Circulatory Support). He quickly recovered and was fully active during follow-up. After 6 months, he first noticed palpitations and experienced episodes of dizziness, which were found to be caused by recurrent ventricular tachycardias. Echocardiography demonstrated a markedly remodeled and downsized left ventricle with improved function. A mechanical irritation of the HVAD inflow touching the inferior-posterior wall was found to trigger these focal arrhythmias. The HVAD was explanted, and no further arrhythmias occurred.

Concomitant surgical atrial fibrillation ablation and event recorder implantation: better monitoring, better outcome?

OBJECTIVES Concomitant ablation is an established therapy in cardiac surgical patients with atrial fibrillation (AF). Post-discharge care seems to be an essential factor for clinical outcome. We analysed the influence of event recorder (ER) implantation and therapy guidance by the results of continuous rhythm monitoring of consecutive postoperative follow-up by our department of electrophysiology. METHODS Between July 2003 and August 2010, 401 cardiac surgical patients underwent concomitant surgical AF ablation therapy. Since August 2009, an ER (REVEAL XT, Medtronic, Inc., Minneapolis, MN, USA) was implanted in 98 patients intraoperatively. ER interrogation was performed by our department of electrophysiology 3, 6 and 12 months postoperatively. Results and outcomes were compared with a matched cohort of patients with ablation and no ER implantation. In those patients, rhythm follow-up was obtained by 24-h Holter ECG. Primary end-point of the study was sinus rhythm rate after 12 months. RESULTS Mean patients age was 67.0 ± 9.7 years, and 68.4% were male. No major ablation-related complications occurred. The overall sinus rhythm rate was 65.3% after 1-year follow-up. The sinus rhythm rate off antiarrhythmic drugs was 60.3%. The conversion rate tended to be higher in patients with an implanted ER (69.3 vs 60.1%, respectively; P = 0.098). Also, the sinus rhythm rate of anti-arrhythmic drugs was higher in the ER group (64.3 vs 56.2). Patients with ER were seen more often by a cardiologist in the first postoperative year (3.1 ± 0.8 vs 1.5 ± 0.9; P < 0.05) and received significantly more additional procedures, like electrical cardioversion or additional catheter-based ablation (16.1 vs 4.3%; P < 0.001; 11.2 vs 3.1%; P < 0.001). CONCLUSIONS Implantation of an ER with link-up to a cardiology and/or electrophysiology provides optimized anti-arrhythmic drug management and higher rates of consecutive procedures like cardioversion or additional catheter-based ablation. As a result, a trend to higher sinus rhythm conversion rate was observed after 1-year follow-up.