Prevention of pacemaker lead induced tricuspid regurgitAtion by transesophageal eCho guidEd implantation (PLACE Pilot)

Background

Lead-induced tricuspid regurgitation (TR) is a frequent complication after pacemaker- and ICD-implantation that is associated with increased mortality and hospitalizations.

Purpose

The aim of this pilot study was to investigate if lead implantation guided by transesophageal echocardiography (TEE) is feasible and might be able to reduce lead-associated TR.

Methods

21 patients with indication for new pacemaker/ICD including a trans-tricuspid lead implantation and TR < grade 2+ were prospectively enrolled and underwent TEE-guided lead implantation in addition to fluoroscopy. Leads were placed according to a dedicated echo protocol with focus on a transgastric en face view of the tricuspid valve targeting a lead position in a tricuspid valve commissure (preferentially postero-septal) and an apical ventricular lead position. (Figure 1) Transthoracic echocardiography (TTE) was performed before implantation and at discharge. 121 consecutive patients with standard lead implantation guided by fluoroscopy only served as a historical control group. TR was assessed by an experienced cardiologist and graded according to current guidelines.

Results

Key baseline characteristics of overall 124 patients with a mean age of 74 years didn't differ between groups. Of note, there was no significant difference regarding device type and baseline TR.

TEE-guided lead implantation was possible in all 21 patients in the TEE-group in deep conscious sedation without occurrence of serious adverse events. Lead placement in a commissure, mostly postero-septal, was possible in 95.2% of patients without worsening of TR (20/21 pts). Based on TEE-guidance, lead position or length was altered in 52.4% of patients (11/21 pts, 6 pts with lead repositioning, 5 pts with modification of lead length).

Compared to baseline, the 21 patients in the TEE-group did not show worsening of TR at discharge. In contrast, TR worsening by one grade occurred in 13.6% of patients (14/103 pts) with new onset of TR ≥2+ in 6.8% of patients (07/103 pts) in the control group (p=0.001).

At discharge, lead position was evaluated using 2D and 3D TTE in a subset of patients. In all examined patients (14/14 pts) lead position was unchanged compared to intraprocedural position and stable during inspiration vs. expiration as well as in upright vs. horizontal position.

Conclusion

TEE-guidance during PM/ICD-implantation was safe and feasible and resulted in steps to optimize lead position in a relevant number of patients. At discharge lead position remained stable and TEE-guided lead implantation was associated with less worsening of TR than standard lead implantation guided by fluoroscopy.

Funding Acknowledgement

Type of funding sources: None. TEE view with targeted lead position

Successful pulmonary thromboendarterectomy for right atrial thrombosis in a heart transplant recipient: a case report

Acute massive or submassive pulmonary embolism is a life-threatening condition with a poor prognosis. It causes sudden hemodynamic deterioration and warrants immediate surgery. We report the case of a 41-year-old male heart transplant recipient who had not been treated prophylactically for thrombosis, who was referred to our center because of exertional dyspnea after immobilization owing to an injury in one of his legs. Transesophageal echocardiography revealed a large, mobile, right atrial mass originating from a pacemaker lead. Furthermore, contrast-enhanced computed tomography scanning of the chest revealed multiple pulmonary emboli resulting in subtotal occlusion of both pulmonary arteries. Although typically reserved for patients with chronic thromboembolic pulmonary hypertension, surgical thromboendarterectomy was successfully performed. Six months after discharge, the patient is well and has a New York Heart Association class 1 rating. This is the first report of a successful pulmonary thromboendarterectomy in a heart transplant recipient.

Fluvastatin as co-medication in heart transplant recipients with elevated creatine-kinase

BACKGROUND

Statins reduce the risk for transplant vasculopathy and mortality among heart transplant recipients. Interactions between commonly used statins (ie, simvastatin, atorvastatin) and immunosuppressant drugs lead to side effects or withdrawal of statin therapy. Fluvastatin shows fewer interactions with the immunosuppressant agents because it is not metabolized via the cytochrome P-450 3A4 pathway like most immunosuppressants, steroids, or other statins. This study investigated the impact of a switch from other statins to fluvastatin in heart transplant recipients who revealed elevated creatine-kinase levels.

METHODS

A total of 23 heart transplant patients with elevated creatine-kinase levels were included in this study. Statins were replaced with an equal dosage of fluvastatin. We measured on the day of replacement as well as there after at 3, 6, 9, and 12 months creatine-kinase, lipid status, ALT, AST, and creatinine levels.

RESULTS

After 6 months creatine-kinase showed a significant reduction of 25% (P < .05) and after 9 months of 38% (P < .05). The HDL-cholesterol levels were significantly reduced at 6 months (8%; P < .05) and 9 months (23%; P < .05). At 3 months, triglyceride levels were significantly elevated (18%; P < .05). No differences were observed in ALT, AST, creatinine, total, and LDL-cholesterol at any time.

CONCLUSION

A conversion from commonly used statins to fluvastatin in heart transplant patients with elevated creatine-kinase was safe, leading to a significant reduction in creatine-kinase levels. Except for an initial raise in triglycerides and a lowering of HDL-cholesterol, no changes in lipid status were seen. This conversion might help to maintain lipid-lowering therapy in transplant recipients who show side effects using conventional statins.

Systemic versus local application of gentamicin in prophylaxis of implant-related osteomyelitis in a rat model

Administration of perioperative antibiotic prophylaxis is a routine procedure in orthopedic surgery. Besides systemic prophylaxis, only few techniques are established for local application of antibiotics to reduce infection related to orthopedic implants. The aim of this study was to evaluate the efficacy of locally versus systemically applied gentamicin in a rat model (n = 60). For local application, the antibiotic was delivered from a biodegradable poly(D,L-lactide) (PDLLA) coating of titanium implants. The efficacy of local prophylaxis was compared to a systemic single shot application of gentamicin as well as a combination of both administrations. Half of the animals received a weight-adopted single shot application of gentamicin 30 min prior to surgery. At surgery, the medullary cavities of the tibiae were contaminated with Staphylococcus aureus (10(2) colony forming units /CFU) and titanium Kirschner wires were implanted into the medullary canals. The implants were either uncoated, PDLLA coated, or coated with PDLLA + 10% w/w gentamicin. The animals were followed up for 42 days. X-ray examinations were performed; body weight, temperature, and the clinical condition were determined. After sacrifice, infection was evaluated by histological and microbiological analysis. All animals treated with uncoated or PDLLA-coated Kirschner wires without systemic application of the antibiotic developed osteomyelitis and all cultures of implants were tested positive on S. aureus. Implant-related osteomyelitis could be prevented by prophylaxis of systemically applied gentamicin in 15% of animals. In contrast, local application of gentamicin delivered from a PDLLA coating was more effective. Onset of infection could be prevented in 90% of animals treated with gentamicin coated Kirschner wires, and in 80% of the animals that were treated with a combination of local and systemic application. The local application from PDLLA-coated implants might support systemic antibiotic prophylaxis in preventing implant-associated osteomyelitis.

A new model of implant-related osteomyelitis in rats

Infection related to osteosynthesis often has dramatic consequences for the patient. Prolonged hospitalization with systemic antibiotic therapy, several revision procedures, possible amputation, and even death may occur. To investigate the pathology of infection in orthopedic surgery, a new rat model of implant related osteomyelitis was developed. Three different concentrations (10(6), 10(3), and 10(2) colony-forming units (CFU)/10 microl) of Staphylococcus aureus were inoculated into the tibial medullary cavity with simultaneous insertion of a titanium Kirschner wire. Controls received phosphate-buffered saline (PBS). Each group consisted of 10 animals. Animals were followed for 4 weeks until sacrifice. X-rays of the tibiae were taken weekly, blood counts were analyzed, and body temperature and weight were determined. After sacrifice, infection was evaluated by histological and microbiological investigations. All animals inoculated with Staph. aureus in either concentration developed microbiological, histological, and radiological signs of osteomyelitis in correlation to the amount of inoculated bacteria. X-rays clearly revealed osseous destruction after 14 days with progression of osteomyelitis during the following weeks. CFU/g bone and bone weight after sacrifice showed dependence on the amount of inoculated CFU. The histological results confirmed the radiological findings. No significant changes in blood counts, body weight, and body temperature between the groups could be observed. The results demonstrate that it is possible to develop a model of implant-related osteomyelitis in rats with dependence on the amount of inoculated bacteria. No other promoters of infection besides intramedullary insertion of titanium Kirschner wires were used in this model.

Gentamicin coating of metallic implants reduces implant-related osteomyelitis in rats

Antibiotic prophylaxis is a routine procedure in orthopedic surgery. Various local antibiotic delivery techniques are used to reduce bone- and soft tissue-related infection. The objective of this study was to evaluate the efficacy of a new biodegradable, gentamicin-loaded poly(D,L-lactide) (PDLLA) coating of orthopedic devices in preventing implant-related osteomyelitis. The medullary cavities of tibiae in 30 Sprague Dawley rats were contaminated with Staphylococcus aureus (10(3) colony forming units). Simultaneously titanium Kirschner wires, uncoated (group II), coated with PDLLA (group III), or coated with PDLLA + 10% gentamicin (group IV), were implanted. Ten animals that received phosphate-buffered saline and uncoated Kirschner wires served as controls (group I). Follow-up was 6 weeks. In weekly intervals X-rays of the tibiae were performed, blood counts were taken, and body temperature and weight were determined. After sacrifice infection was evaluated by histological and microbiological analysis. All animals of groups II and III developed microbiological, histological, and radiological signs of infection, including osseous destruction and soft tissue swelling. All animals of the control group remained sterile. Cultures of implants of group IV showed significantly reduced bacterial growth compared to cultures of groups II and III, and three implants of group IV remained sterile. Further radiological and histological signs of infection were significantly reduced in the gentamicin-coated group compared to groups II and III. No significant differences in body weight, body temperature, and blood parameters between all groups were observed. Local application of antibiotic-coated orthopedic devices containing PDLLA and 10% gentamicin significantly reduced implant-related infection in this animal model.