الفهرس 
CORONARY ORONARY ORONARY MICROCIRCULATIONICROCIRCULATION ICROCIRCULATIONICROCIRCULATIONICROCIRCULATION ICROCIRCULATIONICROCIRCULATIONICROCIRCULATIONICROCIRCULATIONICROCIRCULATIONICROCIRCULATIONICROCIRCULATIONOnly 14 pages are availabe for public view
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Abstract
ngiographic no-reflow is defined as less than TIMI 3 flow or TIMI 3 flow with MBG 0 or 1 without angiographic evidence of mechanical vessel obstruction. [3, 24] No-reflow occurs in >30% of patients after thrombolysis or mechanical intervention for acute myocardial infarction and in 0·6% to 2% of elective PCI. [25]
Persistent no-reflow has been associated with increased mortality and a high incidence congestive heart failure. [25] The pathophysiology of no-reflow encompasses four interacting mechanisms; ischemic injury, reperfusion injury, distal embolization and individual susceptibility. [28] Prevention and treatment of no-reflow are very important to improve cardiovascular outcomes.
Intracoronary route of drug delivery is used in the treatment of no-reflow. Drugs can be injected through the guiding catheter or through a microcatheter or Clearway balloon in the distal coronary bed. In our study we compared the route of drug delivery in the treatment of no-reflow.
In the current study we randomized 40 patients presenting with no-reflow after PCI into two groups. Group 1 (20 patients) was treated by injecting epinephrine and verapamil through the guiding catheter, group 2 (20 patients) was treated by distal drug delivery. Repeated injections were done at the discretion of the operator till best flow is achieved.
We compared both groups regarding the presence of risk factors for CAD, mode of presentation, echocardiographic parameters, angiographic and intervention parameters and outcome. Primary end-point was the achievement of TIMI 3 flow with MBG 2 or 3. Secondary end-points were the occurrence of arrhythmia, hypotension and MACE during hospital stay.
The baseline characteristics including demographic data, risk factors for CAD, mode of presentation, echocardiographic data and pre-injection angiographic data, intervention data were similar between both groups. TIMI flow grades before drug injection were also similar between both groups.
Primary end point (TIMI III with MBG 2 or 3) was achieved more in the distal delivery arm compared to the guiding catheter arm (80% in the distal delivery arm versus 35% in the guiding catheter arm, P= 0.004). In the subgroup of STEMI patients, higher ST-segment resolution was achieved by distal injection compared to guiding catheter injection (77% in the distal delivery arm versus 23% in the guiding catheter arm, P=0.006).
Secondary end points were not different between the two groups although in the guiding catheter arm there was a trend towards increased mortality (15% in the guiding catheter arm versus 5% in the distal delivery arm, P=0.292), occurrence of arrhythmia (25% in the guiding catheter arm versus 10% in the distal delivery arm, P= 0.212) and hypotension (20% in the guiding catheter arm versus 5% in the distal delivery arm, P= 0.151). These inconclusive results regarding secondary endpoints may be due to small number of the study population. The above results were also evident in diabetic patients and patients presenting with STEMI.
The current study showed that distal delivery of epinephrine and verapamil was significantly superior in treating no-reflow compared to IC delivery through the guiding catheter. To the best of our knowledge, this is the first study comparing distal delivery of epinephrine and verapamil to their delivery through the guiding catheter in the treatment of no-reflow phenomenon. Based upon the above results, we recommend the local delivery of drugs into the distal coronary bed in the treatment of no-reflow phenomenon complicating PCI in patients with stable CAD or ACS.