Coronary hyperemic dose responses of intracoronary sodium nitroprusside.
BACKGROUND
Sodium nitroprusside is one of several agents considered effective for treating the no-reflow phenomenon during acute coronary interventions. However, the coronary hyperemic dose responses and systemic hemodynamic effects of intracoronary nitroprusside have yet to be determined in humans. The purpose of this study was to compare the hyperemic and hemodynamic responses of intracoronary nitroprusside to intracoronary adenosine in patients during cardiac catheterization with angiographically normal anterior descending arteries.


RESULTS
In 21 patients, coronary blood flow velocity (0.014-inch Doppler flow wire), heart rate, and blood pressure were measured in unobstructed left anterior descending coronary arteries at rest, after intracoronary adenosine (30- to 50-microg boluses), and after 3 serial doses (0.3-, 0.6-, and 0.9-microg/kg boluses) of intracoronary nitroprusside. Coronary reserve was calculated as hyperemia/basal coronary flow velocity. In an additional 9 patients with intermediate stenoses (53+/-7%), 14 fractional flow reserve (FFR) measurements (using 0.014-inch pressure wire) were performed with both intracoronary adenosine and nitroprusside (0.6 microg/kg). Intracoronary nitroprusside produced equivalent coronary hyperemia with a longer duration ( approximately 25%) compared with intracoronary adenosine. Intracoronary nitroprusside (0.9 microg/kg) decreased systolic blood pressure by <20%, with minimal change in heart rate, whereas intracoronary adenosine had no effect on these parameters. FFR measurements with intracoronary nitroprusside were identical to those obtained with intracoronary adenosine (r=0.97).


CONCLUSIONS
Compared with adenosine, intracoronary nitroprusside produces an equivalent but more prolonged coronary hyperemic response in normal coronary arteries. Intracoronary nitroprusside, in doses commonly used for the treatment of the no-reflow phenomenon, can produce sustained coronary hyperemia without detrimental systemic hemodynamics. On the basis of FFR measurements compared with adenosine, sodium nitroprusside also appears to be a suitable hyperemic stimulus for coronary physiological measurements.
J. Gerard Mudd Cardiac Catheterization Laboratory, St Louis University Health Sciences Center, St Louis, Mo, USA.
Walter A
WA
Parham
Andre
A
Bouhasin
Jeffrey P
JP
Ciaramita
Souheil
S
Khoukaz
Steven C
SC
Herrmann
Morton J
MJ
Kern
D000241:Adenosine / Q000008:administration & dosage / Q000494:pharmacology; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D006328:Cardiac Catheterization; D015897:Comorbidity; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000503:physiopathology*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D003331:Coronary Vessels; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006940:Hyperemia / Q000139:chemically induced*; D007269:Injections, Intra-Arterial; D008297:Male; D008875:Middle Aged; D009599:Nitroprusside / Q000008:administration & dosage / Q000494:pharmacology*; D012307:Risk Factors; D013318:Stroke Volume / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*
D014665:Vasodilator Agents; D009599:Nitroprusside; D000241:Adenosine