The value of hand grip strength (HGS) as a diagnostic and prognostic biomarker in congenital heart disease.

BACKGROUND

In patients with congenital heart disease (CHD), there is little data on the diagnostic and prognostic relevance of hand grip strength (HGS) for clinical assignment, while in the general population the loss of muscle strength and mass is an important risk factor in cardiovascular disease which is conversely associated with morbidity and all-cause mortality. This study aimed to assess the degree of muscle dysfunction using HGS as a biomarker in a large group of patients with CHD who often develop muscle dysfunction.

METHODS

In total, 385 patients (27.6±13.1 years, 43% female) were included and assigned to 5 diagnostic groups: complex anomalies (n=131), left heart anomalies/aortopathies (n=107), right heart/pulmonary artery anomalies (n=92), primary left to-right-shunts (n=42) and miscellaneous CHD (n=13). Patients with Fontan circulation, chronic cyanosis, morphologic right systemic ventricle, arterial switch operation, or Ebstein's anomaly were analyzed separately. A control group (CG) consisted of 124 healthy individuals (30.1±12.1 years, 42% female). HGS was measured with a Jamar Hydraulic Hand Dynamometer.

RESULTS

HGS was reduced in CHD patients compared to controls (35.2±14.6 versus 43.7±14.4 kg). Most impairments were present in females (26.1±7.6 kg). Patients with cyanosis had lower HGS values compared to acyanotic CHD patients (P=0.03). Patients with left heart lesions had the highest HSG values (40.7±14.7 kg), while patients with primary left-to-right shunt lesions had the lowest HSG values (30.9±11.3 kg). Within specific groups of cardiac anomalies, patients with Fontan circulation showed the lowest (P=0.033) and patients with a morphologic right system ventricle showed higher results (P=0.004). The late mid-term survival was favorable, and 7 patients (1.8%) died in a median interval of 422 days (range, 206-1,824 days) after HGS-testing.

CONCLUSIONS

This study provides the most comprehensive data on the use of HGS in CHD to date. Grip strength is an easily applicable, repeatedly usable and a cost-effective diagnostic tool to gain a quick, quantifiable assessment of the patient's current muscle function as an expression of cardiac fitness. Considering the low number of patients who died in the observation period, HGS may not be a suitable tool for survival assessment or identification of patients at risk. However, HGS is well suited to determine muscle function and strength and thereby to identify and to follow-up patients who have an increased cardiovascular risk.