A New Gold Standard in CAD – diagnostics?

Fast, precise, non-invasive, cost-efficient – a broadly based multi centered study analyses
the medical and economic advantages of Cardiogoniometry.

Dr. Sotirios Spiliopoulos, Vera Hergesell, Prof. Dr. Reiner Körfer, Prof. Dr. Gero Tenderich – Abteilung für chirurgische Therapie der terminalen Herzinsuffizienz und Kunstherzversorgung, Evangelisches Klinikum Niederrhein, Duisburg

Among the methods of myocardial perfusion disorder diagnostics Cardiogoniometry (CGM) is a rarely applied procedure. Although this diagnostical tool, implemented by enverdis in 2009, provides various advantages compared to conventional methods, both temporally and economically. The still scarce data basis of the CGM is mainly the reason for these (rarely applied) circumstances. A broadly based multi centered study, by the Protestant Clinic Niederrhein (Evangelisches Klinikum Niederrhein), is supposed to change that for the CAD, vasculopathies and the medical assessment of donor organs.

Cardiogoniometry is a vectorcardiographic method. By means of five surface electrodes an individual, homogenous field of view emerges from which different parameters are extrapolated. These show the e conduction propagation in the myocardium and allow statements on morphologies. Moreover, there  are diagnostic scores for the detection of coronary artery disease with a low voltage, a left or right bundle branch block and atrial fibrillation. The data assessment in the CGM recorder occurs within 12s through bipolar leads, whose fully automatic analysis is available immediately subsequently to the examination. The vectorial sum of cardiac potentials is presented in different display modes. An analysis of the vector loops in twoand three dimensional views as well as the spatial assignments in the maximum vector view helps to draw inferences about areas with perfusion deficits due to reduced potential differences in the myocardium.

CGM shows high quota of sensitivity and specificity with NSTEMI and chronic CAD

CGM is as fast as a diagnosis by ECG, concerning sensitivity and specificity, especially with NSTEMI and chronic CAD, however, it is superior. The Stress ECG, for example, reaches a sensitivity of 67% and a specificity of 72% on patients with chronic CHD/CAD without a prior myocardial infarction. Moreover is the sensitivity of an ECG at only 20% regarding acute coronary syndrome without ST-elevation. With Cardiogoniometry, however, the detection ratio of all patients with NSTEMI was at 85%. In a study involving 696 patients the CGM reached a diagnostic sensitivity of 84% and a specificity of 90% in comparison to coronary angiography.  For further verification concerning quota of sensitivity and specificity with CGM for CHD/CAD the Protestant Clinic for terminal heart failure and artificial heart care Niederrhein (Evangelisches Klinikum Niederrhein) initialized a broadly based study. Therefore a preselected, coronary angiography tested patient group will be ascertained cardiogoniometrically and the results are verified in congruence to the current gold standard of coronary angiography.

 CGM also for detection of transplant vasculopathies and donor organ evaluation?

Additionally two more studies are arranged with the aim, to determine the possibility of implementation of CGM for the detection of transplant vasculopathies as well as donor organ evaluation. The focus of the first study will depict vasculopathies, which describe a limiting factor for long-term survival of patients with heart transplants. Pethig et al recognized that 83% of patients had an angiographically proven prevalence of intima changes ten years after a transplant with a lumen obstruction of 30%.

Additional unfavorable prognostic factors appear to be the above-mentioned occurrence of transplant vasculopathy within the first four years, multi-vessel disease on initial diagnosis and lumen obstruction 50%. For that a high frequency control diagnostic is necessary, which usually occurs by coronary angiography. However, there might be contraindications concerning the contrast agent, which consist due to pre-, peri- and postoperative damages of the kidney, caused by hypertension, diabetes mellitus, catecholamine and antibiotics therapy as well as immunosuppressive drugs. For that the Cardiogoniometry constitutes a stress free and non-invasive alternative. The multi centered study executed by the Protestant Clinic Niederrhein (Evangelisches Klinikum Niederrhein) reviews the findings of this method in contrast to the conventional coronary angiography and compiles parameters, through which a reliable statement according to vasculopathically caused changes of the tunica intima can be gathered. The aim is to establish this method as a control and screening tool.

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Illustration: Cardiogoniometry and related coronary angiography of a 72 years old patient after orthotopic heart transplant in
1990 with dilated cardiomyopathy. The current stationary admission was based on an acute rejection reaction with
echocardiographic verified intensely reduced left ventricular ejection fraction (LVEF 20%). After treatment by cortisone stoss therapy the CGM was recorded. Thereby the suspicion of ischemia / transplant vasculopathy aroused. The indication for coronary angiography was made. In this way the initial diagnosis got verified and the affected arteries were interventionally recanalized.

CGM could decrease the risk of transplant failure

The aim of the second study is the assessment of donor organs before the explantation to improve the outcome after a
transplant. A broadly based study in the year 2007 by Grauhan et al surveyed the repercussions of a donor organ with an
arteriosclerotic heart disease in relation to the transplant success.

1086 patients were a part of this study, whose donor organ had no biopsically ascertained CAD as well as 82 patients, who had a heart with CAD implanted. This group was 7% of the collective. With patients of this group, who had a coronary disease, a higher risk of transplant failure was emerging within the first 30 days. Another aim of this project is the establishment of a non-invasive diagnostics method for conservation of donor organs, due to the relinquishment of contrast agents and invasive methods, that are accompanied by analgetic and hypnotic therapy and therefore have hepatotoxic and nephrotoxic side effects. Furthermore it is possible in cases of a fastly necessary explantation that a good prognostic statement concerning organ quality and therefore an immediate transplant success can occur.

In conclusion must be said, that the CGM has great potential, both economically and medically. These are mirrored on one hand in terms of low monetary expense, which are conditioned by a short diagnostic time and low materials input as well as the possibility to prioritize in terms of patients concerning resource allocation in use of cath lab. On the other hand the Cardiogoniometry constitutes, in terms of non-invasive methods and no use of contrast agents, a less complicated alternative of diagnostics, through which patients and organs are taken care of as good as possible

Original Source:
Spitzenforschung Herz-Kreislauf Medizin
Innovationen und Auszeichnungen 2013