No reflow phenomenon: Insights from 10 case reports

The no-reflow phenomenon refers to inadequate perfusion of a part of the myocardium located downstream of an epicardial artery. It affects 5 to 30% of patients who have undergone reperfusion via angioplasty. Since this phenomenon significantly limits the benefits of reperfusion and is a poor prognostic factor, several studies have focused on analyzing the various pathophysiological mechanisms, which remain a current topic of interest. Its diagnosis relies on a combination of clinical findings, electrocardiogram, coronary flow after angioplasty, and cardiac imaging using MRI. Although medical treatment may improve prognosis, prevention remains the most effective therapeutic approach.
Our study reports the experience of our department through 10 clinical cases of no-reflow during primary coronary angioplasty in the context of acute coronary syndrome with ST-segment elevation, along with a literature review.

Objective of study: The objective of this study is to review the pathophysiology, predictive factors, and diagnostic and therapeutic approaches to the no-reflow phenomenon, by presenting ten clinical cases illustrating this phenomenon in the context of ST-elevation myocardial infarction

Material and methods: This retrospective study, conducted from June 2021 to March 2023 at the Military Hospital of Rabat, included STEMI patients who underwent primary angioplasty and developed the no-reflow phenomenon. Criteria for inclusion included significant flow reduction, failure to reperfuse, high thrombotic burden, persistent ST elevation, and lack of LV function improvement. Ten patients met the criteria after reviewing medical records.

Conclusion: No-reflow is common during the acute phase of myocardial infarction and is an important marker of mortality. Despite the reopening of the culprit artery, distal microcirculation is often impaired. Its pathogenesis is complex and multifactorial. At-risk patients can be identified through simple clinical and angiographic criteria, such as age, delayed recanalization, low TIMI flow, high thrombotic burden, and long lesions. No single therapy is sufficiently effective, and a combined approach involving multiple strategies and addressing risk factors is necessary. Several treatment options are currently under investigation.