Trends of popularity of cardiac biomarkers: Insights from Google Trends

This study was aimed at assessing the trend of worldwide popularity, thus likely reflecting usage, of conventional cardiac biomarkers, including cardiac troponins, myoglobin and creatine kinase MB (CK-MB). Google Trends was interrogated using a combination of the three search terms "troponin" AND "myoglobin" AND "CK-MB", with a time limit set between January 1, 2014 (i.e., the oldest searchable year) and present time (i.e., August 13, 2018). The raw data were entered into an Excel worksheet and reported as cumulative Google Trends scores per week for each cardiac biomarker. The popularity score of myoglobin and CK-MB has displayed a significantly decreasing trend since the 2004, whilst that of troponin has exhibited an apparently paradoxical U-shape behavior, with a more pronounced increase during the past 10 years. The correlation between time and cumulative Google searches was significant for all biomarkers, being r=0.40 (P<0.001) for troponin, r=-0.45 (P<0.001) for myoglobin and r=0.79 (P<0.001) for CK-MB. The score of overall Google searches for troponin was approximately 2.5-fold and 8.5-fold higher than for myoglobin and CK-MB, respectively. When the analysis was limited to the past ten years, the correlation between time and cumulative Google searches became even stronger for troponin (r=0.85; P<0.001), remained virtually identical for CK-MB (r=-0.80; P<0.001), whilst it was no longer significant for myoglobin (r=0.13; P=0.150). The graphical analysis of Google search frequency also showed that CK-MB appears to be popular in Mexico, Brazil, Chile, Japan, Poland and Romania, myoglobin seems popular in Uruguay, Bolivia, Denmark, Kazakhstan and in some African Nations, whilst troponin is mostly predominant in the remaining parts of the world. The results of this study suggest that, despite all available guidelines share the principle that cardiac troponin should be considered the one and only reference biomarker for diagnosing myocardial ischemia, CK-MB and especially myoglobin are still popular worldwide, especially in certain geographic areas.