Real-world experience with the insertion of a new implantable cardiac monitor

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Biotronik SE & Co.KG

OnBehalf

BIO|CONCEPT.BIOMONITOR III study group, BIO|MASTER.BIOMONITOR III study group, BIO|STREAM-ICM study group

Background

Implantable Cardiac Monitors (ICM) provide continuous long-term heart rhythm monitoring. The new ICM BIOMONITOR III / IIIm (BM III) is provided with a single-step insertion tool.

Purpose

To report on the insertion procedure of the BM III in a large real-world patient population.

Methods

The BM III combines a low cross-section (4.5 x 8.5 mm) with an extended ICM length (77 mm, including flexible antenna). It is inserted into subcutaneous tissue with an ‘injection’ tool that forms the pocket and delivers the device in a single step. We report results of the insertion procedure from a pooled data set from the BIO|CONCEPT BM III (completed) and the BIO|MASTER BM III and BIO|STREAM-ICM (ongoing) studies.

Results

From 54 investigational sites in 11 countries, 455 insertions were reported (including 39 BM IIIm). The patients were 63 ± 16 years old, had a BMI of 27.6 ± 5.4, and 43% were women. The indications were syncope or pre-syncope (57%), cryptogenic stroke (23%), management of AF (11%) or other (9%). Insertions took 1.7 ± 1.8 minutes until removal of the insertion tool, 4.7 ± 3.4 minutes until wound closure, and 7.1 ± 5.6 minutes including wound cleaning. The wound was sutured (79%) or closed with staples (10%) or adhesive strips (10%). General anaesthesia was used in 8% of the patients and antibiotic prophylaxis in 50% (44% systemic and 6% local). Insertions took place in the catheter laboratory (62%), operating theatre (22%) or in a consultation room (16%) without specific precautional equipment.

The insertion site was parallel to the heart"s long axis (56%), parasternal (39%), in the 2nd/3rd intercostal space (3.5%), axillary (0.9%) or at the clavicula (0.7%). The device was repositioned in one case (0.2%). 13 adverse events were reported in connection to the insertion procedure. 5 cases of device pocket bleeding or hematoma occurred. In 5 further cases, the device migrated, posing the risk of extrusion, or actually extruded. Three of these cases used only adhesive strips or no wound closure at all. In two cases, an incorrect usage of the incision tool and substantial subcutaneous fatty tissue may have contributed. One device was damaged by a 200 J defibrillation shock with a shock electrode placed over the device. One patient suffered from dyspnoea, possibly due to psychogenic hyperventilation. One patient had a vasovagal syncope due to pain after an insertion with insufficient local anaesthesia. No infections were reported until the day of analysis, which was more than 30 days after insertion in 92% of all cases.

Conclusion

The new BM III was inserted in typically less than 5 minutes until wound closure. A relevant number of insertions took place in a consultation room. Prophylactic antibiotics may be unnecessary, because no pocket infections were reported, although no antibiotic prophylaxis was used in one half of all cases (N = 229). In summary, the insertion with the new tool is fast and has a low risk of complications.

Papillary thyroid carcinoma after recombinant GH therapy for Turner syndrome

Turner syndrome (TS) has been included for several years among the indications for GH treatment, generally with satisfactory outcomes. Nevertheless, the long-term effects of this treatment in non-GH deficient patients are not fully known. The incidence of thyroid carcinoma is rare in patients during childhood, it is unusual to find this neoplasia in children under sixteen years old. This article reports the cases of two Spanish patients with papillary thyroid carcinoma after GH treatment for TS. Recent studies have indicated a possible relationship between the GH-IGF axis and the pathogenesis of neoplasias, questioning the chance association of these two pathologies. In line with this, we detected GH receptor expression in the papillary carcinoma cells. Long-term prospective studies are required to clarify the possible effects of GH treatment on the risk of neoplasia.

Genetic basis of short stature

Growth in humans is a complex process controlled by many genetic and non-genetic factors. It is influenced by endogenous factors like genetics, hormones and metabolism as well as exogenous ones like nutrition, physical activity and psychosocial status. Growth is one of the most sensitive markers of children's health, their nutritional status and genetic background. Besides, deviation from normality may be the first manifestation of an underlying congenital or acquired pathology. Thus, it is important to know the growth process and the disorder that can disturb it. Short stature is defined as a condition in which the height of an individual is more than 2 SD below the corresponding mean height for a given age, sex and population group. This disorder is a major concern for patients and their parents, and represents a diagnostic challenge to the clinician. A correct diagnosis is particularly important in view of the availability of effective, but costly, therapy in a small subset of cases. Cytogenetic and molecular analysis can be of great value in this diagnostic process. Emphasis can be made on the advances of molecular genetics, which have characterized human genes involved in the hypothalamus-pituitary-GH axis such as GH, POU1F1, PROP1, GHRHR, GHR, IGF, IGFR, HESX1, LHX3, LHX4, among others. Our current line of investigation is related to the study of some of these genes and the genotype-phenotype relation with the aim of identifying features that add some more light on the genetic origins of short stature.

Therapeutic optimization of growth hormone deficiency in children and adolescents

More than 40 years after the introduction of growth hormone (GH) treatment, many questions remain unanswered. Clearly, with the availability of rhGH and with current treatment protocols, treatment efficacy has improved. However, it still remains unclear whether current treatment protocols are the best possible. Before GH deficiency was recognized as a chronic disease, children only received treatment until normal adult height had been reached. However, it has recently been shown that not all GH-dependent body structures and functions normalize in parallel with height. Furthermore, in adolescents with GH deficiency, the interruption of GH substitution leads to severe hormone deficiency symptoms in adulthood. In the case of an adolescent who meets the biochemical criteria for GH deficiency in adulthood, but does not show alterations of metabolism, body structure, or emotional state, should GH treatment be started in adolescence, or only if and when the clinical syndrome becomes apparent? This is a difficult question to which there is not yet any clear answer, and we suggest that there is a need for further studies in this area. Furthermore, it will be necessary to re-evaluate the situation of patients who have completed their growth, and definitive conclusions will require controlled studies.