Impact of dye injection on intracoronary pressure

AIMS: Coronary angiography is widely used to estimate coronary blood flow velocity, as in the TIMI frame count method. However, it is unknown to what extent the injection of dye elevates intracoronary pressure which may accelerate coronary blood flow velocity. In the present study, intracoronary pressure was measured during coronary angiography. METHODS AND RESULTS: In 25 patients with non-significant coronary lesions, assessed by fractional flow reserve measurement with a pressure guidewire, we recorded intracoronary pressure during dye injection for coronary angiography in the ostium of the coronary artery as well as distal to the lesion. There was a rise in mean intracoronary pressure during dye injection in both ostial and distal coronary arterial segments (from 90.8 +/- 17.2 mmHg to 96.8 +/- 18.5 mmHg and from 89.7 +/- 15.3 mmHg to 93.6 +/- 17.3 mmHg, respectively; p<0.001). Nevertheless, the absolute and relative increase in pressure was small (6.0 +/- 4.2 mmHg [6.7 +/- 4.9%] in the ostium, and 3.9 +/- 5.5 mmHg [4.2 +/- 5.7%] distally). CONCLUSIONS: In coronary arteries without significant stenosis, coronary angiography causes only a minor increase in intracoronary pressure. The limited impact of dye injection on intracoronary blood pressure confirms the value of coronary angiography for estimation of coronary flow velocity

Endothelial Dysfunction After ST-segment Elevation Myocardial Infarction and Long-term Outcome: A Study With Reactive Hyperemia Peripheral Artery Tonometry

Introduction and objectives: Long-term data on the relationship between endothelial dysfunction after ST-segment elevation myocardial infarction and future adverse clinical events are scarce. The aim of this study was to noninvasively assess whether endothelial dysfunction 4 to 6 weeks after primary percutaneous coronary intervention for acute ST-segment elevation myocardial infarction predicts future clinical events. Methods: This prospective cohort study was performed in 70 patients of the RESPONSE randomized trial, who underwent noninvasive assessment of endothelial function 4 to 6 weeks after primary percutaneous coronary intervention. Endothelial function was measured by the reactive hyperemia peripheral artery tonometry method; an index < 1.67 identified endothelial dysfunction. Results: The reactive hyperemia peripheral artery tonometry index measured on average 1.90 ± 0.58. A total of 35 (50%) patients had endothelial dysfunction and 35 (50%) patients had normal endothelial function. Periprocedural “complications” (eg, cardiogenic shock, total atrioventricular block) were more common in patients with endothelial dysfunction than in those without (25.7% vs 2.9%; P < .01). During 4.0 ± 1.7 years of follow-up, 20 (28.6%) patients had major adverse cardiovascular events: events occurred in 9 (25.7%) patients with endothelial dysfunction and in 11 (31.5%) patients with normal endothelial function (P = .52). There was an association between the prevalence of diabetes mellitus at baseline and the occurrence of major adverse cardiovascular events during follow-up (univariate analysis: hazard ratio = 2.8; 95% confidence interval, 1.0-7.8; P < .05), and even in multivariate analyses the risk appeared to be increased, although not significantly (multivariate analysis: hazard ratio = 2.5; 95% confidence interval, 0.8-7.5). Conclusions: In this series of patients who survived an ST-segment elevation myocardial infarction, endothelial dysfunction, as assessed by reactive hyperemia peripheral artery tonometry 4 to 6 weeks after myocardial infarction, did not predict future clinical events during a mean follow-up of 4 years

Endothelial Dysfunction After ST-segment Elevation Myocardial Infarction and Long-term Outcome: A Study With Reactive Hyperemia Peripheral Artery Tonometry

Long-term data on the relationship between endothelial dysfunction after ST-segment elevation myocardial infarction and future adverse clinical events are scarce. The aim of this study was to noninvasively assess whether endothelial dysfunction 4 weeks to 6 weeks after primary percutaneous coronary intervention for acute ST-segment elevation myocardial infarction predicts future clinical events. This prospective cohort study was performed in 70 patients of the RESPONSE randomized trial, who underwent noninvasive assessment of endothelial function 4 weeks to 6 weeks after primary percutaneous coronary intervention. Endothelial function was measured by the reactive hyperemia peripheral artery tonometry method; an index <1.67 identified endothelial dysfunction. The reactive hyperemia peripheral artery tonometry index measured on average 1.90±0.58. A total of 35 (50%) patients had endothelial dysfunction and 35 (50%) patients had normal endothelial function. Periprocedural "complications" (eg, cardiogenic shock, total atrioventricular block) were more common in patients with endothelial dysfunction than in those without (25.7% vs 2.9%; P <.01). During 4.0±1.7 years of follow-up, 20 (28.6%) patients had major adverse cardiovascular events: events occurred in 9 (25.7%) patients with endothelial dysfunction and in 11 (31.5%) patients with normal endothelial function (P=.52). There was an association between the prevalence of diabetes mellitus at baseline and the occurrence of major adverse cardiovascular events during follow-up (univariate analysis: hazard ratio=2.8; 95% confidence interval, 1.0-7.8; P <.05), and even in multivariate analyses the risk appeared to be increased, although not significantly (multivariate analysis: hazard ratio=2.5; 95% confidence interval, 0.8-7.5). In this series of patients who survived an ST-segment elevation myocardial infarction, endothelial dysfunction, as assessed by reactive hyperemia peripheral artery tonometry 4 weeks to 6 weeks after myocardial infarction, did not predict future clinical events during a mean follow-up of 4 year

Endothelial function after ST-elevation myocardial infarction in patients with high levels of high-sensitivity CRP and Lp-PLA2: A substudy of the RESPONSE randomized trial

The combination of high levels of high-sensitive C-reactive protein (hs-CRP) and lipoprotein-associated phospholipase-A2 (Lp-PLA2) was recently shown to correlate with increased cardiovascular risk. Endothelial dysfunction is also known to be a risk factor for cardiovascular events. To test among patients with previous ST-elevation myocardial infarction (STEMI) the hypothesis that high levels of both hs-CRP and Lp-PLA2 may be associated with impaired endothelium-dependent vasodilatation. In this substudy of the RESPONSE randomized trial, we used reactive hyperemia peripheral artery tonometry (RH-PAT) 4 to 6weeks after STEMI and primary percutaneous coronary intervention (PPCI) to non-invasively assess endothelial function (RH-PAT index 239μg/L, respectively). Patients were 57.4±9.7years and 53 (77.9%) were men. 11 (16%) patients were classified as high-risk and 57 (84%) as low-to-intermediate-risk. The RH-PAT index was 1.68±0.22 in high-risk and 1.95±0.63 in low-to-intermediate-risk patients (p=0.17). Endothelial dysfunction was present in 8 (72.7%) high-risk and 26 (45.6%) low-to-intermediate-risk patients (p=0.09). Framingham risk score, NT-proBNP and fibrinogen levels were higher in high-risk patients (p≤0.03). In this population of patients with recent STEMI and PPCI, we observed between patients with high hs-CRP and Lp-PLA levels and all other patients no more than numerical differences in endothelial function that did not reach a statistical significance. Nevertheless, further research in larger study populations may be warrante

Serial assessment of endothelial function 1, 6, and 12 months after ST-elevation myocardial infarction

Knowledge about the changes in endothelial function after ST-elevation myocardial infarction (STEMI) is of substantial interest, but serial data are scarce. The aim of the present study was to noninvasively evaluate whether endothelial function, as assessed shortly after primary percutaneous coronary intervention (PPCI) for STEMI, may improve until 12-month follow-up. This prospective observational cohort study was performed in patients in the RESPONSE randomized trial who participated in a substudy and underwent noninvasive assessment of endothelial function at 1 (baseline), 6, and 12-month follow-up after treatment of a STEMI by PPCI. The reactive hyperemia peripheral artery tonometry (RH-PAT) method was used to assess endothelial function (higher RH-PAT index signifies better function). Of the 70 study participants, who were 57.4 ± 9.7 years of age, 55 (78.6%) were male and 9 (13%) had diabetes. The endothelial function deteriorated significantly during follow-up: the RH-PAT index at baseline, 6, and 12-month follow-up was 1.90 ± 0.58, 1.81 ± 0.57, and 1.69 ± 0.49, respectively (p = 0.04). Although patients were carefully treated in outpatient clinics and adequate pharmacological therapy was prescribed, we noted an increase in total cholesterol (p = 0.001), LDL cholesterol (p = 0.002), HbA1C (p = 0.054), and diastolic blood pressure (p = 0.047) However, multivariate analysis revealed that this increase in cardiovascular risk factors could not explain the observed deterioration in endothelial function. In patients with STEMI, we observed a significant deterioration in endothelial function during 12 months after PPCI that could not be explained by changes in the traditional cardiovascular risk profile

Assessment of the relation between initial culprit vessel patency in acute ST-elevation myocardial infarction and endothelial function

To assess whether better endothelial function increases the likelihood of patients with acute ST-elevation myocardial infarction (STEMI) having initially patent culprit vessels. Clinical data on the relation between endothelial function and culprit vessel patency in STEMI patients are scarce. In this prospective cohort study in 71 patients with STEMI, endothelial function was non-invasively assessed by use of the reactive hyperaemia peripheral artery tonometry (RH-PAT) method at four to six weeks after the primary percutaneous coronary intervention (PPCI). The RH-PAT index measured on average 1.90±0.58. In patients with patent culprit vessels before PPCI (n=33, 46.5%), endothelial function was significantly better than in patients with occluded vessels (n=38, 53.5%) (RH-PAT index 2.08±0.34 vs. 1.75±0.35; p <0.007). Compared to patients with normal endothelial function, the patients with severe endothelial dysfunction had a fivefold higher risk of presenting with an occluded culprit vessel (OR 5.1, 95% CI: 1.8-14.2). Logistic regression analysis revealed that this relation between endothelial function and vessel patency became even stronger after adjustment for potential confounders (adjusted OR 7.1, 95% CI: 2.1-23.6). In this series of patients with acute STEMI, better endothelial function was independently associated with a higher likelihood of presenting with an initially patent culprit vesse