Distal Embolization of Hydrophilic-Coating Material From Coronary Guidewires After Percutaneous Coronary Interventions

BACKGROUND—Coronary guidewires are indispensable during percutaneous coronary interventions. Nowadays, most guidewires have hydrophilic coatings to improve their trackability, allowing easy lesion passage and facilitating balloon and stent positioning. Recent reports, however, have raised concerns about detachment and subsequent embolization of these hydrophilic coatings. METHODS AND RESULTS—We have retrospectively reviewed the histological samples of the myocardium, obtained during autopsies in the period 2009 to 2013, from all patients who had a history of percutaneous coronary interventions (n=40). Foreign material was observed in the distal myocardium in 4 patients (10%). Furthermore, we have reviewed 205 thrombus specimens which were obtained during thrombus aspiration in the setting of primary percutaneous coronary interventions in the period 2005 to 2009. In 45% of the cases, foreign material was observed within the thrombus. Finally, we have examined the histopathologic appearance of hydrophilic-guidewire coating material ex vivo by embedding the coating in placenta specimen and cut and stain it in exactly the same manner as the myocardium and thrombus specimen. The histopathologic appearance of the hydrophilic coating ex vivo was identical to the foreign material found in vivo. CONCLUSIONS—Distal embolization of hydrophilic-coating material was observed in 10% of the patients who had a history of percutaneous coronary interventions. Hydrophilic-coating material was found in 45% of coronary thrombus specimen obtained during thrombus aspiration. These findings suggest that detachment and distal embolization of hydrophilic-coating material from coronary guidewires occur more often than the sparse literature on this topic suggests.