Risk of pacing-induced cardiomyopathy in patients with high-degree atrioventricular block – comparison between right ventricular pacing sites using computed tomography

Background

Right ventricular (RV) pacing may induce significant left ventricular (LV) dyssynchrony resulting in pacing-induced cardiomyopathy (PICM). LV activation sequence is affected by RV pacing site and previous studies suggest that RV septal pacing may be superior compared to traditional RV apical pacing. However, results are conflicting and randomized controlled trials have failed to show clear benefits from RV septal pacing. Traditionally, studies have applied fluoroscopy to determine RV lead implantation site. However, locating pacing site using this method is known to be inaccurate and poorly reproducible compared with cardiac computed tomography (CT). The purpose of our study was to evaluate the association between RV pacing site determined by cardiac CT and risk of PICM.

Methods

We retrospectively included 153 patients with pre-implant LV ejection fraction (LVEF) ≥50% who underwent fluoroscopy-guided dual chamber pacemaker implantation due to high-degree atrioventricular block between March 2012 and May 2020. All patients attended a follow-up visit including cardiac CT and transthoracic echocardiography. RV lead position was evaluated from CT dividing the RV into three segments: apical, septum or free wall (Figure 1). Furthermore, RV lead position estimated by the implanting physician, using fluoroscopy during pacemaker implantation, was retrieved from medical records. The primary endpoint was PICM defined as ≥10% decrease in LVEF from time of pacemaker implantation to follow-up, resulting in LVEF <50%.

Results

Mean duration of follow-up was 3.7 years (range 2.1–8.7). The implanting physician estimated 131 (85.6%) leads to be located septal, 5 (3.3%) located non-septal and 17 (11.1%) were unknown. Based on CT, 48 (31.4%) leads were located septal and 105 (68.6%) were located non-septal of which 31 were located on the free wall (20.4%). With CT as the golden standard, 47 (35%) leads were estimated correctly during fluoroscopy-guided implantation. No significant differences between patient characteristics in the CT-estimated septal and non-septal groups were observed except for ischemic heart disease (P=0.05) (Table 1). There were 16 (33.3%) patients in the septal group who developed PICM compared to 31 (29.5%) in the non-septal group (P=0.6). Adjusting for ischemic heart disease did not change this result. In the septal group, the change in LVEF from baseline to follow-up was −9.0±10.4% compared to −7.5±9.1% in the non-septal group (P=0.4).

Conclusion

In total 31% developed PICM despite having a normal pre-implant LVEF with no observed difference between RV septal and non-septal pacing. With CT as the golden standard, RV leads were inaccurately located during fluoroscopy-guided pacemaker implantation with only 35% being located correctly. Misclassification of pacing sites in previous studies may have contributed to the inconsistent results.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Svend Andersens FondKarl G Andersens Fond

Soft-tissue sarcoma of the thigh: surgical margin influences local recurrence but not survival in 152 patients

Between 1979 and 1998, 152 patients with a soft-tissue sarcoma arising in the thigh were surgically treated in the Sarcoma Center in Aarhus, Denmark. We studied clinicopathologic factors prognostic for local recurrence and survival. 27 patients (18%) had a low-grade tumor, 26 (17%) an intermediate-grade and 99 (65%) a high-grade tumor. 27 patients (18%) were amputated and 125 (82%) had a local resection. 21 (14%) underwent a marginal resection, 82 (54%) a wide resection and 49 (32%) a compartmental resection. 32 patients were also given radiotherapy, 11 of these had a marginal resection. The 5-year local recurrence-free rate was 91%. Multivariate analysis selected marginal resection and histological high grade as unfavorable prognostic factors for local recurrence. The 5-year survival rate was 68%. High age and histological high grade were unfavorable prognostic factors for survival in a multivariate analysis. Surgical margin influenced local recurrence, but not the overall survival.

[Prognostic factors in soft tissue sarcomas. Experiences from the Sarcoma Center in Aarhus]

In the present study, the outcome, patterns of local recurrence and survival, as well as prognostic factors, were evaluated in patients surgically treated for soft tissue sarcomas. Between January 1979 and July 1993, 316 consecutive patients were referred to the Sarcoma Centre in Aarhus with localised malignant soft tissue sarcoma of the extremities or trunk. There were 161 men (51%) and 155 women (49%), the median age was 56 years (1-94). Histologically 52 patients (16%) had a grade I, 60 patients (19%) a grade 2 and 204 patients (65%) a grade 3A or 3B tumour. The five-year local recurrence rate was 18% and the five-year survival rate was 75%. Multivariate analysis indicated the following variables as independent unfavourable factors for local recurrence: extracompartmental location, histological high-grade (i.e. histologically highly malignant) local excision, no adjuvant radiotherapy and intralesional/marginal excision. Independent unfavourable factors for survival were advanced age, extracompartmental location, histological high-grade, lower extremity location and large tumour size. Based on these variables, a prognostic model was made.

Prognostic factors in soft tissue sarcomas: the Aarhus experience

In the present study, the outcome, patterns of local recurrence and survival, as well as prognostic factors, were evaluated in patients surgically treated for soft tissue sarcomas. Between January 1979 and July 1993, 316 consecutive patients were referred to the Sarcoma Centre in Aarhus with localised malignant soft tissue sarcoma of the extremities or trunk. If possible, the patients were treated with a limb-sparing resection, primarily by use of a wide excision. 50 patients received adjuvant radiotherapy. There were 161 men (51%) and 155 women (49%) median age 56 years (range 1-94 years). 94 patients (30%) had tumours in the trunk, including shoulder and buttock lesions, 163 (52%) in the lower extremity and 59 (19%) in the upper extremity. 52 patients (16%) had grade 1 tumour, 60 (19%) grade 2 and 204 (65%) grades 3A-3B. The 5-year local recurrence rate was 18% and the 5-year survival rate was 75%. Multivariate analysis indicated the following variables as independent unfavourable factors for local recurrence: extracompartmental location, histological high grade, local excision, no adjuvant radiotherapy and intralesional/marginal excision. Independent unfavourable factors for survival were advanced age, extracompartmental location, histological high grade, lower extremity location and large tumour size. If the variable local recurrence was included in the analysis, it was found to have a very strong influence on survival. Based on these variables, a prognostic model was developed.