Clinical & Experimental Cardiology
Open Access
ISSN: 2155-9880
ISSN: 2155-9880
Takashi Koyama
Saitama Municipal Hospital, Japan
Keynote: J Clin Exp Cardiolog
My colleagues and I recently reported a new approach, postconditioning with lactate-enriched blood (PCLeB), for preventing reperfusion injury in patients with ST-segment elevation myocardial infarction (STEMI). This approach targets reperfusion-induced hypercontracture, which compresses the microvasculature and mechanically disrupts myocardial cell skeletons. PCLeB comprises intermittent reperfusion and timely coronary injections of lactated Ringerâ�?�?s solution (Figure 1), aiming to achieve controlled reperfusion with tissue oxygenation and minimal lactate washout. This approach was designed based on the results of our previous experimental study. We have reported that abrupt lactate washout during reperfusion after simulated ischemia induced contracture in guinea-pig myocytes despite a substantial decrease in intracellular Ca2+ concentrations ([Ca2+]i), which were elevated during simulated ischemia. This reperfusion-induced contracture developed in association with resensitization of myofilaments to Ca2+. We therefore attempted to create a transition period between ischemia and reperfusion through our new approach. During this transition period, the elevated [Ca2+]i was allowed to resume its normal level safely, while restoration of vigorous myocardial contraction was suspended by keeping tissue lactate concentrations high, which otherwise might lead to hypercontracture. We have treated 76 consecutive patients with STEMI (age, 65.5 �?± 14.1 years; 77.6% men; 43.4% anterior STEMI) using percutaneous coronary intervention and PCLeB within 12 h of symptom onset since late 2011. No patient experienced ventricular tachycardia or fibrillation during reperfusion. After PCI, corrected TIMI frame count was 20.4 �?± 11.1 (normal value, 21). Peak creatine kinase and creatine kinase-MB levels were 2707 �?± 2099 and 264 �?± 170 IU/L, respectively. No patient died or experienced worsening/new-onset heart failure at 30 days. Only one patient required oral diuretic therapy at discharge. In conclusion, PCLeB induced augmented microcirculation recovery, abolished reperfusion arrhythmia, and led to zero mortality and no worsening/new-onset heart failure at 30 days in 76 consecutive patients with STEMI. Related publications 1. Koyama T, Shibata M, Moritani K. Ischemic postconditioning with lactate-enriched blood in patients with acute myocardial infarction. Cardiology 2013; 125: 92-93. 2. Koyama T, Niikura H, Shibata M, Moritani K, Shimada M, Baba A, Akaishi M, Hideo M. Impact of ischemic postconditioning with lactate-enriched blood on early inflammation after myocardial infarction. IJC Metab Endocr 2014; 2: 30-34. 3. Koyama T, Niikura H, Shibata M, Munakata M, Kageyama T, Akima T, Kanki H, Moritani K, Ishikawa S, Mitamura H. Possible creatine kinase washout mechanism revealed by postconditioning with lactate-enriched blood in patients experiencing STelevation myocardial infarctions. Int J Cardiol 2014; 177: 492-493. 4. Koyama T, Kageyama T, Munakata M, Nagaoka M, Akima T, Kanki H, Ishikawa S. Muscle squeezing of the culprit coronary artery in a patient with ST-elevation myocardial infarction after postconditioning with lactate-enriched blood. Int J Cardiol 2015; 182: 77-78. 5. Koyama T, Munakata M. Akima T, Kanki H, Ishikawa S. An extensive discrepancy in myocardial uptake of thallium-201 and iodine-123 BMIPP in a patient with ST-segment elevation myocardial infarction treated using postconditioning with lactateenriched blood. Int J Cardiol 2015;198:51-52. 6. Munakata M, Koyama T, Akima T, Kanki H, Ishikawa S. Minimum ischemia-reperfusion injury in a STEMI patient treated using postconditioning with lactate-enriched blood. Int J Cardiol 2016; 202:282-284. 7. Koyama T, Munakata M, Akima T, Kageyama T, Shibata M, Moritani K, Kanki H, Ishikawa S, Mitamura H. Impact of postconditioning with lactate-enriched blood on in-hospital outcomes of patients with ST-segment elevation myocardial infarction. Int J Cardiol 2016;220:146-148. 8. Akima T, Koyama T, Munakata M, Shibata M, Moritani K, Kanki H, Ishikawa S, Mitamura H. Absence of reperfusion-induced arrhythmia in patients with ST-segment elevation myocardial infarction treated using postconditioning with lactate-enriched blood. Int J Cardiol 2016;222:780-781. 9. Koyama T. Lactated Ringerâ�?�?s solution for preventing myocardial reperfusion injury. Int J Cardiol Heart Vasc 2017;15:1-8 (review).
Koyama is currently a vice director of the Saitama Municipal Hospital in Saitama, Japan. He has expertise in research in myocardial reperfusion injury. He has recently developed a new treatment strategy for myocardial reperfusion injury in patients with ST-segment elevation myocardial infarction (STEMI), based on the results of his previous experimental study using guinea-pig myocytes that was published in Am J Physiol in 1991. He is basically a clinical cardiologist, performing percutaneous coronary intervention himself. But his experiences not only in STEMI treatment but also in animal experiments inspired him to develop a new treatment strategy for myocardial reperfusion injury, i.e. postconditioning with lactate-enriched blood. He has already published a review paper on this new approach in IJC Heart & Vasculature, claiming that the new approach may be effective against all four types of myocardial reperfusion injury.
Email:koyamas@me.com