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Coronary pressure and flow relationships in humans: phasic analysis of normal and pathological vessels and the implications for stenosis assessment: a report from the Iberian – Dutch – English (IDEAL) collaborators

View Article: PubMed Central - PubMed

ABSTRACT

Background: Our understanding of human coronary physiological behaviour is derived from animal models. We sought to describe physiological behaviour across a large collection of invasive pressure and flow velocity measurements, to provide a better understanding of the relationships between these physiological parameters and to evaluate the rationale for resting stenosis assessment.

Methods and results: Five hundred and sixty-seven simultaneous intracoronary pressure and flow velocity assessments from 301 patients were analysed for coronary flow velocity, trans-stenotic pressure gradient (TG), and microvascular resistance (MVR). Measurements were made during baseline and hyperaemic conditions. The whole cardiac cycle and the diastolic wave-free period were assessed. Stenoses were assessed according to fractional flow reserve (FFR) and quantitative coronary angiography DS%. With progressive worsening of stenoses, from unobstructed angiographic normal vessels to those with FFR ≤ 0.50, hyperaemic flow falls significantly from 45 to 19 cm/s, Ptrend < 0.001 in a curvilinear pattern. Resting flow was unaffected by stenosis severity and was consistent across all strata of stenosis (Ptrend > 0.05 for all). Trans-stenotic pressure gradient rose with stenosis severity for both rest and hyperaemic measures (Ptrend < 0.001 for both). Microvascular resistance declines with stenosis severity under resting conditions (Ptrend < 0.001), but was unchanged at hyperaemia (2.3 ± 1.1 mmHg/cm/s; Ptrend = 0.19).

Conclusions: With progressive stenosis severity, TG rises. However, while hyperaemic flow falls significantly, resting coronary flow is maintained by compensatory reduction of MVR, demonstrating coronary auto-regulation. These data support the translation of coronary physiological concepts derived from animals to patients with coronary artery disease and furthermore, suggest that resting pressure indices can be used to detect the haemodynamic significance of coronary artery stenoses.

No MeSH data available.


Related in: MedlinePlus

Mean TG, flow velocity and MVR data under resting conditions over the whole cardiac cycle, stratified according to angiographic stenosis severity. With progressive stenosis severity, TG increases, while flow velocity is maintained at a stable level by progressive compensatory reduction of MVR. Curves are fitted by 2nd, 3rd order and fractional polynomials.
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EHV626F6: Mean TG, flow velocity and MVR data under resting conditions over the whole cardiac cycle, stratified according to angiographic stenosis severity. With progressive stenosis severity, TG increases, while flow velocity is maintained at a stable level by progressive compensatory reduction of MVR. Curves are fitted by 2nd, 3rd order and fractional polynomials.

Mentions: In contrast, TG (Figure 5, lower panel) whether measured at rest or hyperaemia, had strong and significant relationships with stenosis severity and followed identical trends, also for the wave-free period (Ptrend < 0.001 for all assessments). Hyperaemic TG was strongly related to FFR (R2 = 0.95, P < 0.001). The behaviour of flow, MVR and TG over the whole cycle under resting conditions for the entire study cohort is summarized in Figure 6.Figure 6


Coronary pressure and flow relationships in humans: phasic analysis of normal and pathological vessels and the implications for stenosis assessment: a report from the Iberian – Dutch – English (IDEAL) collaborators
Mean TG, flow velocity and MVR data under resting conditions over the whole cardiac cycle, stratified according to angiographic stenosis severity. With progressive stenosis severity, TG increases, while flow velocity is maintained at a stable level by progressive compensatory reduction of MVR. Curves are fitted by 2nd, 3rd order and fractional polynomials.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940452&req=5

EHV626F6: Mean TG, flow velocity and MVR data under resting conditions over the whole cardiac cycle, stratified according to angiographic stenosis severity. With progressive stenosis severity, TG increases, while flow velocity is maintained at a stable level by progressive compensatory reduction of MVR. Curves are fitted by 2nd, 3rd order and fractional polynomials.
Mentions: In contrast, TG (Figure 5, lower panel) whether measured at rest or hyperaemia, had strong and significant relationships with stenosis severity and followed identical trends, also for the wave-free period (Ptrend < 0.001 for all assessments). Hyperaemic TG was strongly related to FFR (R2 = 0.95, P < 0.001). The behaviour of flow, MVR and TG over the whole cycle under resting conditions for the entire study cohort is summarized in Figure 6.Figure 6

View Article: PubMed Central - PubMed

ABSTRACT

Background: Our understanding of human coronary physiological behaviour is derived from animal models. We sought to describe physiological behaviour across a large collection of invasive pressure and flow velocity measurements, to provide a better understanding of the relationships between these physiological parameters and to evaluate the rationale for resting stenosis assessment.

Methods and results: Five hundred and sixty-seven simultaneous intracoronary pressure and flow velocity assessments from 301 patients were analysed for coronary flow velocity, trans-stenotic pressure gradient (TG), and microvascular resistance (MVR). Measurements were made during baseline and hyperaemic conditions. The whole cardiac cycle and the diastolic wave-free period were assessed. Stenoses were assessed according to fractional flow reserve (FFR) and quantitative coronary angiography DS%. With progressive worsening of stenoses, from unobstructed angiographic normal vessels to those with FFR &le; 0.50, hyperaemic flow falls significantly from 45 to 19 cm/s, Ptrend &lt; 0.001 in a curvilinear pattern. Resting flow was unaffected by stenosis severity and was consistent across all strata of stenosis (Ptrend &gt; 0.05 for all). Trans-stenotic pressure gradient rose with stenosis severity for both rest and hyperaemic measures (Ptrend &lt; 0.001 for both). Microvascular resistance declines with stenosis severity under resting conditions (Ptrend &lt; 0.001), but was unchanged at hyperaemia (2.3 &plusmn; 1.1 mmHg/cm/s; Ptrend = 0.19).

Conclusions: With progressive stenosis severity, TG rises. However, while hyperaemic flow falls significantly, resting coronary flow is maintained by compensatory reduction of MVR, demonstrating coronary auto-regulation. These data support the translation of coronary physiological concepts derived from animals to patients with coronary artery disease and furthermore, suggest that resting pressure indices can be used to detect the haemodynamic significance of coronary artery stenoses.

No MeSH data available.


Related in: MedlinePlus