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Coronary hemodynamics before and after rotational atherectomy with adjunctive balloon angioplasty
B D Núñez1, E T Keelan, S T Higano
1Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
Insights
Rotational atherectomy temporarily reduces coronary flow, potentially due to microvascular issues, but vasodilators can restore it. Combined procedures improve hemodynamics but not flow reserve, suggesting device-independent mechanisms.
Area of Science:
- Cardiology
- Interventional Cardiology
- Cardiovascular Physiology
Background:
- The no-reflow phenomenon is a known complication after rotational atherectomy.
- Coronary artery disease management often involves procedures to restore blood flow.
Purpose of the Study:
- To assess coronary hemodynamic changes using Doppler flow wire after rotational atherectomy and balloon angioplasty.
- To investigate the impact of these interventions on coronary flow and microvascular function.
Main Methods:
- Doppler flow wire measurements of coronary hemodynamics in 10 patients before and after procedures.
- Assessment of TIMI flow, Cineframes to opacification, lumen diameter, coronary flow, maximal velocity, vascular resistance, and coronary flow reserve.
- Administration of intracoronary nitroglycerin and verapamil.
Main Results:
- Rotational atherectomy alone reduced coronary flow (TIMI grade decrease) and increased opacification time, reversible with vasodilators.
- Adjunctive balloon angioplasty improved lumen diameter, coronary flow, maximal velocity, and decreased vascular resistance.
- Coronary flow reserve did not improve after either rotational atherectomy alone or combined procedures.
Conclusions:
- Rotational atherectomy can cause transient coronary flow reduction, possibly via microvascular spasm or obstruction, responsive to vasodilators.
- While improving macrovascular parameters, combined interventions do not enhance coronary flow reserve.
- The lack of improvement in flow reserve suggests device-independent mechanisms that require further investigation.
Abstract:
The phenomenon of "no-reflow" has been described frequently after rotational atherectomy. The aim of this study was to determine the coronary hemodynamic changes by Doppler flow wire before and after rotational atherectomy and adjunctive balloon angioplasty in 10 patients. All patients had TIMI-III flow at baseline. After rotational atherectomy alone, two patients had TIMI-I, four patients had TIMI-II, and four patients had TIMI-III flow. In addition, the number of Cineframes to Opacification of a preselected distal landmark increased twofold (from 49 +/- 12 to 118 +/- 27 frames; P < 0.05). Intracoronary nitroglycerin and verapamil was associated with return to baseline of both measurements. Following adjunctive balloon angioplasty, there was an increase in lumen diameter (1.29 +/- 0.1 vs. 2.6 +/- 0.1 mm; P < 0.05), coronary flow (81 +/- 14 to 154 +/- 18 ml/min; P < 0.05), maximal absolute velocity (23 +/- 4 to 52 +/- 4 cm/sec; P < 0.05), and vascular resistance decreased (1.74 +/- 0.4 to 0.74 +/- 0.4 mm Hg/ml/min; P < 0.05). However, no change in coronary flow reserve was noted (1.24 +/- 0.1 vs. 1.5 +/- 0.3). Immediately after rotational atherectomy alone, there is a reduction in angiographically determined coronary flow, suggesting either distal microvascular spasm or distal microvascular obstruction. Regardless of the mechanism, the transient reduction of coronary flow was rapidly reversed by coronary vasodilators. Despite the significant improvement of coronary hemodynamics noted immediately after combined rotational atherectomy and balloon angioplasty, coronary flow reserve remained abnormal. Similarly, no change in coronary flow reserve has been reported immediately after balloon angioplasty alone. The lack of improvement in flow reserve after both balloon angioplasty and rotational atherectomy suggests that the mechanisms of improved flow reserve may be device independent, and remain unexplained.