Identifying predictive risk factors for permanent pacemaker implantation up to 30 days post-TAVI

Background

Conduction system abnormalities, including AV block, are amongst the most common complications of transcatheter aortic valve implantation (TAVI). Post-TAVI high degree AV block necessitates permanent pacemaker (PPM) implantation.

Purpose

To assess the ability of standardly available pre-, intra- and post-TAVI factors to predict PPM implantation within 30-days post procedure.

Methods

Demographic and clinical (pre-, intra-, and post-procedural) data including ECG parameters were collected from all patients who underwent TAVI at our centre from August 2017 to November 2020. Patients with pre-existing PPM were excluded from the study. Predictive factors were selected through univariate analysis, and selected characteristics were incorporated into a multivariate binomial logistic regression model, in order to create a 30-day PPM risk-prediction model. The Akaike information criterion (AIC) and area under receiver operating curve (AUC/C-statistic) were used to assess discriminative performance.

Results

In total, data from a total of 446 patients were analysed. Of these, 40 (8.97%) received PPM implantation within 30 days of the procedure. The mean age of the patients was 81.5 (±7.3 SD) years; 99 (22.2%) had pre-existing first degree AV block, 55 (12.3%) had pre-existing left bundle branch block (LBBB) and 50 (11.2%) had pre-existing right bundle branch block (RBBB). Intra-procedurally 40 (9.0%) developed LBBB, 21 (4.7%) developed 3rd degree AV block, and 95 (21.3%) patients required temporary pacing wire (TPW) pacing. Post-procedurally, 138 (30.9%) exhibited AV block, 107 (24.0%) LBBB and 50 (11.2%) RBBB.

The following factors met significance at multivariate logistic regression analysis: pre-TAVI RBBB (OR 6.62 [95% CI, 1.37–36.51]), intra-TAVI 3rd degree AV block (OR 12.80 [95% CI, 3.44–53.34]), intra-TAVI LBBB (OR 4.02 [95% CI, 1.28–12.53]), use of TPW pacing (OR 8.58 [95% CI, 3.19–25.12]) and post-TAVI LBBB (OR 7.84 [95% CI, 2.75–24.46]) (Table).

Finally, variables were incorporated into a multivariate logistic regression model with the outcome variable of 30-day PPM implantation (Figure 1a). A model incorporating five factors (pre-TAVI RBBB, intra-TAVI 3rd degree AV block, intra-TAVI LBBB, use of TPW pacing and post-TAVI LBBB) demonstrated excellent discriminative ability (accuracy 0.925 and an AUC of 0.952) at predicting PPM implantation (Figure 1b).

Conclusions

Following variable selection, the best performing model incorporated five factors including pre-TAVI RBBB, intra-TAVI AV block (3rd degree), intra-TAVI LBBB, use of TPW pacing and post-TAVI LBBB. We aim to validate this model using an external cohort.

Funding Acknowledgement

Type of funding sources: None. Table 1Figure 1

Phytoestrogen intake and cardiovascular risk markers in Bangladeshi postmenopausal women

Menopause is the transitional event of female life creating a considerable degree of clinical and psychological as well as social problem and it is known to affect the risk markers of cardiovascular diseases. Hormone replacement therapy (HRT) was though to be a cornerstone in the management of menopause, but evidences accumulated in the recent past have raised serious questions regarding its safety and usability. In this context, phytoestrogens are getting increasingly more attention for therapeutic (as an alternate of HRT) and dietary interventions. Menopause is a special problem for women in developing countries and intake of phytoestrogens can be highly useful also from the economic point of views. The nutraceuticals of specific vitamins, minerals and especially phytoestrogens supplementations are a vital component of the strategy to reduce health problem. The present study was aimed to assess the association of phytoestrogens and risk markers of cardiovascular diseases in postmenopausal women. A total of 111 postmenopausal subjects [age, (years, M±SD) 52±5.35] were studied. The dietary intake of phytoestrogens by study subjects was calculated by a specific food frequency questionnaire (FFQ). Serum fasting homocysteine was measured by AxSYM system. Serum glucose was estimated by glucose-oxidase method. Serum total cholesterol, triglyceride and HDL-C were estimated by enzymatic-colorimetric method LDL-C was estimated by the Friedewald's formula. The intake of total phytoestrogens, isoflavones and lignans (mean±SD, mg/day) were 7.65±3.33, 0.32±0.16, 7.32±3.28 respectively in postmenopausal women. The intake of diadzein, genistein, formononetin, biochanin A (mean±SD, mg/day) were 0.085±0.035, 0.168±0.101, 0.074±0.052 and 0.001±0.0008 respectively. The intake of matairesinol and secoisolaiciresinol (SILR) (mean±SD, mg/day) were 0.022±0.006 and 7.30±3.28 respectively. The total phytoestrogens (r=-0.19, p=0.03) and SILR, one specific type of lignans (r=-0.19, p=0.04) consumption in this study were inversely significantly associated with serum glucose level. The dietary formononetin, one specific type of isoflavones was negatively significantly associated with LDL-cholesterol (r=-0.18, p=0.04). There was no significant relationship found between phytoestrogen intake and serum homocysteine level (r=-0.11, p=0.23). Phytoestrogens containing food intake should be encouraged for reducing risk markers of cardiovascular disease in postmenopausal women.

[A trial of molecular diagnosis in Leber's optic neuropathy]

The high frequency of mitochondrial DNA mutation at the nucleotide position (nt) 11,778 was reported in cases of Leber's hereditary optic neuropathy (LHON) after the first report by Wallace et al.. We already reported that it provided a simple diagnostic test by means of PCR (polymerase chain determined the diagnosis of LHON in a case. No nt 11,778 mutation was found in patients with the other optic nerve diseases and in normal controls. This shows the usefulness of molecular diagnosis in LHON. Problems of genetic counselling for patients and female carriers and the possibilities to clarify the cause of LHON were discussed.

A mutation of mitochondrial DNA in Japanese families with Leber's hereditary optic neuropathy

Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease characterized by optic nerve degeneration associated with severe bilateral visual loss in young men and occasionally in women. A mitochondrial DNA (mtDNA) replacement mutation in LHON patient, G to A transition at nucleotide position (nt) 11778 converting the 340th arginine to histidine in the NADH dehydrogenase subunit 4, was detected as SfaNI site polymorphism (Wallace et al., Science, 242: 1427-1430, 1988). To evaluate if the SfaNI site loss can be used to diagnose LHON patients, mtDNAs from peripheral blood of six affected males including five probands from five unrelated Japanese families with LHON, a pair of parents and a normal sister of one of the probands and 4 control persons were analyzed using PCR amplification method. The mutation of leukocyte mtDNA at nt 11778 was identified in all of the affected patients, the normal mother and the sister examined, while the father who is normal and 4 control persons did not show the change. These findings support that the mutation at nt 11778 is also associated with LHON in the Japanese and the test of the SfaNI site loss described here is useful for confirming the clinical diagnosis of LHON patients with the mutation at nt 11778.

Outbreak of gastroenteritis in different areas of Pakistan

Outbreak of acute gastroenteritis occurred during July to August, 1988 in districts of Mansehra, Swat and Muzaffarabad. Thirty cases, clinically diagnosed as cholera, were investigated. On examination, 22 (73.3%) cases were bacteriologically confirmed as cholera due to V. cholerae Eltor, ogawa. All strains were sensitive to chloramphenicol.

Ultrasonography in the diagnosis of obstructive jaundice

Ultrasonography was employed in the diagnosis of obstructive jaundice. In a group of 38 patients who were studied, Ultrasonography was found to be reliable in confirming the diagnosis. In majority of the cases it was also found to be reliable in revealing the cause of obstruction. Nineteen of these patients were examined by percutaneous transhepatic cholangiography (PTC) and there were 100 per cent correlation with Ultrasonography. Twelve of these patients underwent operation and the findings were in good agreement with those of Ultrasonography.

Study of thyroid functions in protein energy malnutrition

Thyroid functions were studied in eight children suffering from PEM. The assessment of thyroid functions were done by measuring serum T3 and T4 levels by radioimmunoassay. Both T3 and T4 levels in serum were significantly (P less than 0.001) reduced in PEM as compared to normal healthy children. These results suggest that thyroid functions are affected in PEM. The impairment of such functions may possibly be due to a deficiency of protein or to a blockade in the incorporation of iodine into thyroid hormone at some stage after iodide transport into the gland. The possibility of alteration of some biochemical or metabolic changes induced by PEM during biosynthesis of thyroid hormones cannot be excluded.