Coronary flow velocity monitoring after angioplasty associated with abrupt reocclusion

Cyclic flow variations after angioplasty: a rare phenomenon predictive of immediate complications. DEBATE Investigator's Group

Experimental studies and studies in human beings have indicated that cyclic flow variation (CFV) is a reliable marker of the formation of platelet aggregates and thus may be predictive of immediate complications after coronary angioplasty. In this study, the incidence and clinical relevance of CFV in a large patient population after elective percutaneous transluminal coronary angioplasty (PTCA) was assessed. One hundred two patients with one-vessel disease and no previous Q-wave myocardial infarction underwent angiographically successful PTCA of a single lesion of a major coronary artery. A Doppler guide wire inserted distal to the stenosis was used to monitor flow velocity continuously after PTCA for 15 minutes. In 94 (92%) of 102 patients, a stable and reliable Doppler signal could be recorded for 15 minutes after the procedure. CFV, defined as gradual decline in flow over several minutes followed by a sudden restoration to higher values, was observed in 4 patients. In 3 of these 4 patients, the occurrence of CFV was predictive of immediate complications (2 intracoronary thrombosis and 1 acute closure), whereas none of the patients without CFV (n = 90) showed acute closure during hospital stay. In conclusion, CFVs in patients after angiographically successful elective PTCA are rare (4.3%) but highly sensitive for the prediction of abrupt occlusion.

Continuous coronary flow velocity monitoring during coronary interventions: velocity trend patterns associated with adverse events

Continuous measurement of blood flow velocity during interventional procedures has the potential to provide an early warning of coronary flow instability, which can lead to abrupt closure or other adverse events before angiography. The magnitude and fluctuations of the average velocity over time (trend) was studied by using a 0.018-inch Doppler-tipped angioplasty guide wire in 32 patients after coronary angiography (n = 20), atherectomy (n = 2), urgent stent (n = 6), urgent vein graft thrombolysis (n = 4), or acute myocardial infarction (n = 2). The patients (mean age 60 +/- 11 years) had postprocedural in-laboratory flow monitoring for a mean of 19 +/- 11 (range 8 to 36) minutes. The coronary artery monitored was the left anterior descending in 13, circumflex in 6, right coronary artery in 9, and saphenous vein graft in 4. Seven patients had flow-related events during continuous flow velocity monitoring before serial angiographic study. These events included coronary vasospasm (abrupt flow acceleration), vasovagal flow cessation, cyclical flow variations resulting from accumulation of intraluminal thrombus, and rapid decline of flow velocity. The last two patterns were associated with abrupt vessel closure during angioplasty. Continuous flow velocity monitoring is easily incorporated into routine interventional procedures and provides an early indication of unstable flow and the potential for abrupt vessel closure and other adverse events.

Alterations of coronary flow velocity during intervention for acute myocardial infarction: responses to complications of intracoronary thrombolysis and angioplasty

Alterations, either an increase or decrease, in the distal flow velocity over time are associated with alterations in vessel diameter and/or unstable flow velocity. Unexplained unstable flow velocity patterns should act as early warning signs to prompt the interventionalist to assess continued coronary patency and need for renewed interventions.