Growth differentiation factor 15 (GDF 15) is not expressed in the normal adult heart but is up regulated in cardiomyocytes via multiple stress pathways. It has been associated with mortality in patients with heart failure. While right ventricular (RV) pacing is an important and effective treatment in patients with atrioventricular block it has been shown to promote left ventricular dysfunction.

This study aimed to investigate the role of GDF 15 as marker for chronic RV pacing.

 

In this single-center prospective cohort study data from 265 consecutive patients (60.4 % male) with single or dual chamber pacemaker and no preexisting heart failure who presented in the outpatient department for routine follow-up was analyzed. Chronic RV pacing was defined as > 40 % within the last year. Serum blood samples were drawn and GDF 15 determined using a commercially available immunoassay (R&D Systems Inc., Minneapolis). Student’s t-test was performed to test for group differences and receiver operating characteristics (ROC) to illustrate the diagnostic ability.

 

Chronic RV pacing was found in 67.2 % of patients. Baseline patients’ characteristics are shown in table 1. When separated by stimulation threshold GDF 15 was significantly elevated among patients > 40 % compared to those ≤ 40 % (789 ± 293 pg/ml versus 1,186 ± 592 pg/ml; p < 0.001), see figure 1. ROC revealed GDF 15 as a marker for chronic RV pacing with an area under the curve of 0.713 (95 % confidence interval 0.650 – 0.776; p < 0.001), see figure 2.

 

In this pilot-study GDF 15 was identified as potential marker for chronic RV pacing.

 

Table 1. Baseline patients’ characteristics.

	All
Sex male [%]	60.4
Age [years]	72.1 ± 11.4
Body mass index [kg/m2]	27.3 ± 4.8
Single chamber pacemaker [%]	19.6
Dual chamber pacemaker [%]	80.4
Pacing threshold ventricle [%]	62.5 ± 41.4
Pacing threshold atrium [%]	10.4 IQR 52.1
Left ventricular ejection fraction [%]	54.3 ± 5.8
Hypertension [%]	81.5
Type II diabetes [%]	21.2
Coronary artery disease [%]	26.4
Chronic kidney disease [%]	23.0
Atrial fibrillation [%]	63.4
Mode switch [%]	1.0 IQR 1.825

IQR = interquartile range

Figure 1. GDF 15 levels separated by pacing threshold of 40 %.

Figure 2. Receiver operating characteristics for GDF 15 levels and chronic RV pacing.