A potential connection between heart and hand

24.07.2023 17:22

The so-called carpal tunnel syndrome is a painful entrapment of the median nerve, is very common in Germany and is one of the main causes of hand operations. Recently, it was suspected for the first time that the syndrome could be associated with heart failure. This thesis has now been confirmed using a retrospective cohort study by Prof. Karel Kostev, head of epidemiology at IQVIA Frankfurt, in collaboration with the cardiologist Dr. Mark Luedde (CAU University, Kiel) further verified: The risk of new-onset heart failure was higher in adult patients with carpal tunnel syndrome than in patients without the syndrome.

The study, which is based on IQVIA's Disease Analyzer database, included 163,796 anonymous patient profiles from 1,284 general practitioner practices. Half of the study population had received the initial diagnosis of carpal tunnel syndrome, the other half (n = 81,898 participants) had not. The patient-based information was retrospectively reviewed for the period from January 2005 to the end of 2021 and merged so that there were no differences in both cohorts in terms of age, gender and relevant comorbidities.

The evaluations showed that after 10 years, 8.4 % of patients with carpal tunnel syndrome and 6.2 % of patients without such syndrome received a diagnosis of heart failure. The incidence was 8.7 cases versus 6.1 cases per 1000 patient-years and the risk of heart failure is 39 % more likely in observation profiles with a history of carpal tunnel syndrome and increases with age. The potential for new-onset heart failure (HF) is therefore higher in people with carpal tunnel syndrome (CTS) than in people without this neuroanatomical disease.

“This requires attention,” explains Prof. Kostev

“Heart failure is associated with high mortality and we know that a weak heart diagnosed as early as possible improves the prognosis in the further course of treatment,” explains Kostev. But how does the association between an inflammatory disease in the hand and heart failure come about? A possible explanation could be a third clinical picture, namely amyloidosis, the incorrect folding of a protein. In this case, the blood protein transthyretin, which can no longer be broken down from the blood as the disease progresses and is deposited.

Interestingly, in both cohorts, the researchers found in further analysis that amyloidosis was detected in 0.06 % of the study group and 0.02 % of the control group. There were 47 patients in the cohort with carpal tunnel syndrome and 17 patients in the cohort without hand syndrome. Karel Kostev: “Statistically, it also shows that patients with the syndrome have an 80 percent increased risk of also developing amyloidosis. So it could be that carpal tunnel syndrome is an early symptom of amyloidosis. Something similar has also been discussed in recent studies. And since transthyretin amyloidosis is a systemic disease as protein deposits in the blood, it also affects the heart muscle and its functions as the disease progresses; heart failure and cardiac arrhythmias are known as amyloidosis progresses. Our study could be a first indication of connections between these pathological changes and processes.”

Further research should now follow and be encouraged, said the epidemiologist. In the present study, there was uncertainty about the proportion of patient-based information regarding the presence of amyloidosis and no balance could be achieved in the cohorts. Furthermore, Prof. Kostev emphasizes that not every case of carpal tunnel syndrome is associated with amyloidosis and that not every amyloidosis also causes heart failure. The scientists will now continue to investigate what connections there are.

Original publication

Mark Luedde, MD; Volker Jürgen Schmidt, MD; Julia Gänsbacher-Kunzendorf, MD; Karel Kostev, PhD, “Association Between Carpal Tunnel Syndrome and Subsequent Heart Failure Among Adults in Germany”, doi:10.1001/jamanetworkopen.2023.23091