Impact of the Pulmonary Index of Microcirculatory Resistance in Pulmonary Arterial Hypertension
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 22
- 试验地点
- 1
- 主要终点
- PIMR change from baseline
研究概览
简要总结
The chief regulator of resistance in pulmonary arterial hypertension (PAH) is the small arteries. In the heart, the invasive measurement of the resistance of the small arteries has been shownto be safe, easy, reliable, and prognostic. This study is intended to translate prior work in heart arteries to the PAH space and invasively measure the resistance of the small arteries of the lung (pulmonary index of microcirculatory resistance [PIMR]) and the coronary artery supplying the right ventricle (acute marginal of the RCA; RV-IMR). Importantly, these measurements will be made during standard of care cardiac catheterizations (right heart catheterization [RHC] +/- left heart catheterization). The correlation between these new indices and the standard ones measured during RHC typically used to determine the severity of pulmonary hypertension will be analyzed. In addition, among newly diagnosed patients, the study will evaluate how these indices change 6 months after starting treatment. Finally, the association of these indices with clinical outcomes at 1 year will be assessed. The findings from this study may deliver an immediate impact to patient care by identifying a new metric to help better identify those who may benefit from a more intensive, personalized treatment regimen.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Diagnosis of Group 1 PAH with invasive pulmonary hypertension defined as: Mean pulmonary arterial pressure ≥ 20 mmHg, pulmonary capillary wedge pressure < 15 mmHg, and pulmonary vascular resistance ≥ 3 Wood units.
- •Serum creatinine < 2.0 mg/dL
- •Able to provide informed written consent
排除标准
- •Other groups/forms of pulmonary hypertension (i.e. groups 2-5)
- •Contraindicated to undergo fluoroscopy and/or coronary angiography
- •Pregnancy
结局指标
主要结局
PIMR change from baseline
时间窗: Baseline, 6 months only if repeat RHC as standard of care
PressureWire advanced to distal third of segmental pulmonary artery (PA) for measurement of pulmonary hemodynamics. The derivation of IMR involves the application of Ohm's law (V=IR) to the coronary microcirculatory circuit, where the relationship between resistance (R) = IMR, voltage (V) = pressure (P), and current (I) = flow (Q) can be expressed as follows: IMR = ∆P/Q. ∆P = the change in pressure across the microvasculature (mean distal coronary artery pressure \[Pd\] - coronary venous pressure (Pv); Pv is typically disregarded because it is negligible relative to Pd. Based on the principles of thermodilution, flow is inversely proportion to mean transit time (Q \~ 1/Tmn). Lastly, the minimal achievable resistance occurs during maximal hyperemic flow when all available microvessels have theoretically been recruited. Hence, the calculation of IMR simplifies to the following formula: IMR = Pd (pulmonary artery) x TmnHyp.
PAH hospitalization or all-cause mortality at 1 year
时间窗: 1 year
The primary outcome is the composite of PAH hospitalization or all-cause mortality at 1 year.
RV-IMR
时间窗: Baseline
PressureWire advanced to distal third of acute marginal branch of the right coronary artery (RCA) for measurement of pulmonary hemodynamics. The derivation of IMR involves the application of Ohm's law (V=IR) to the coronary microcirculatory circuit, where the relationship between resistance (R) = IMR, voltage (V) = pressure (P), and current (I) = flow (Q) can be expressed as follows: IMR = ∆P/Q. ∆P = the change in pressure across the microvasculature (mean distal coronary artery pressure \[Pd\] - coronary venous pressure (Pv); Pv is typically disregarded because it is negligible relative to Pd. Based on the principles of thermodilution, flow is inversely proportion to mean transit time (Q \~ 1/Tmn). Lastly, the minimal achievable resistance occurs during maximal hyperemic flow when all available microvessels have theoretically been recruited. Hence, the calculation of IMR simplifies to the following formula: IMR = Pd (RCA marginal branch) x TmnHyp.
次要结局
未报告次要终点
研究者
Rushi V. Parikh
Principal Investigator
University of California, Los Angeles