Therapeutic effect in heart patients predictable
Arrhythmias are very common – especially in the elderly and people who already have another heart disease. Then they have to be treated in most cases. Researchers are now reporting that the therapeutic effect can be predicted from the breathing rate.
Like the Technical University of Munich (TUM) in a current Message writes, arrhythmias are among the most common heart diseases. A study led by Prof. Georg Schmidt from TUM shows for the first time that the nocturnal breathing rate can help with an important prediction: It shows whether a defibrillator has a life-prolonging effect on people with cardiac arrhythmias or not.
Benefits of defibrillator therapy
According to the information, sudden cardiac death is one of the most common causes of death in western industrialized nations. It can be prevented by implanting a cardioverter defibrillator (ICD). This automatically detects dangerous rhythm disturbances and then terminates them with electrical impulses.
The guidelines recommend the implantation of an ICD in patients with significantly reduced pumping function of the left ventricle. According to the German Heart Report, more than 42,000 defibrillators were implanted in Germany in 2018.
The effect of the implantation of the ICD is sometimes questionable. The current heart report of the German Heart Foundation also notes that the benefits of defibrillator therapy are not as pronounced as previously assumed. In addition, the benefits are often offset by complications during or after the insertion of the implant.
Nightly breathing rate
Researchers at TUM have now shown that the nocturnal breathing rate of cardiac patients, which has so far been neglected, can be used as a predictor for the success of an ICD treatment.
Between May 2014 and September 2018, the scientists observed a total of 1,971 patients with heart disease in 44 European heart centers. 1,363 of the sick received a cardioverter defibrillator implanted, the control group was treated conservatively.
According to the communication, the respective treatment options were determined by the different availability of ICD therapy in the participating European centers. It is therefore a non-randomized study, in which the resulting distortions in the results were compensated for by sophisticated statistical analysis methods. The study has now been published in “eClinicalMedicine“-Open-access journal of the renowned specialist journal“ Lancet ”.
In both groups, the researchers measured the average nightly breathing rate between midnight and 6 a.m. on the basis of an ECG protocol. The defibrillator wearers had a survival advantage of 31.3 percent compared to the control patients.
At the same time, there was a significant correlation between a lower nightly breathing rate and reduced mortality: ICD wearers with a frequency of less than 18 breaths per minute had a survival advantage of 50 percent compared to the control group thanks to the device. With a higher nightly breathing rate, however, the ICD did not give them any survival advantage.
“The respiratory rate is a biosignal that has been largely ignored in cardiology up to now,” says Prof. Georg Schmidt, head of the biosignal processing group at the TUM Klinikum rechts der Isar and last author of the study.
“Our findings are now bringing this parameter back into focus.” The scientific study proves the predictive power of the breathing rate for the therapeutic effect. “Especially in borderline cases, a look at the respiratory rate can make the therapy decision easier.”
Aimed at randomized examination
Against this background, the expert, who also chairs the TUM ethics committee, considers it justifiable to aim for a randomized study against the established guidelines in the next step.
“Those patients in whom we did not observe any benefit from the ICD implantation in our study would be divided into two groups. While one group is implanted with an ICD, the other is treated conservatively, ”explains Prof. Schmidt.
“If such a randomized study shows that cardiac patients with a high nocturnal breathing rate do not benefit from the ICD implantation, they could be spared the operation in the future.” (Ad)
Author and source information
This text corresponds to the requirements of the medical literature, medical guidelines and current studies and has been checked by medical professionals.
- Technical University of Munich (TUM): Respiratory rate predicts therapy effect in heart patients, (accessed: December 21, 2020), Technical University of Munich (TUM)
- M. Dommasch, A. Steger, G. Schmidt et. al.: Nocturnal respiratory rate predicts ICD benefit: A prospective, controlled, multicentre cohort study; in: EClinicalMedicine, (veröffentlicht: 21.12.2020), ClinicalMedicine
This article is for general guidance only and is not intended to be used for self-diagnosis or self-treatment. He can not substitute a visit at the doctor.