Vascular endothelial growth factor protein levels and gene expression in peripheral monocytes after stenting: a randomized comparative study of sirolimus: eluting and bare metal stents.

AIMS: Although previous studies have indicated that vascular endothelial growth factor (VEGF) plays an important role in the vascular-healing process after stent implantation, its effect on in-stent restenosis is unclear. We assessed VEGF serum protein levels and gene expression in peripheral monocytes in relation to in-stent restenosis after implantation of sirolimus-eluting (SES) and bare metal stents (BMS) in a non-blinded, randomized study. METHODS AND RESULTS: Forty-two patients (28 men, age 62 +/- 11 years) with stable angina, who underwent elective single-vessel percutaneous coronary intervention, were randomized to SES (n = 21) or BMS (n = 21) implantation. VEGF protein levels in the BMS group showed an increasing trend (P = 0.083), whereas in the SES group they decreased significantly (P = 0.002). BMS induced up-regulation of VEGF mRNA levels, whereas for SES down-regulation was observed. There was no correlation between serum levels and late luminal loss. A significant correlation was found between VEGF gene expression and late luminal loss in both groups (BMS: r = 0.98, P < 0.001; SES: r = 0.65, P = 0.002). CONCLUSION: SES, in comparison with BMS, results in lower VEGF protein levels and gene expression in peripheral monocytes. The latter shows a positive relationship with in-stent late-luminal loss, suggesting an essential role in the reduced in-stent restenosis seen in SES.

Acute effect of esmolol intravenously on coronary microcirculation in patients with idiopathic dilated cardiomyopathy.

Although coronary flow reserve (CFR) impairment was correlated with the prognosis of patients with idiopathic dilated cardiomyopathy (IDC) and microvascular ischemia was implicated in the progress of the disease, little is known about the effect of the established therapy with beta blockers on coronary microcirculation. The purpose of this study was to assess the effect of beta(1) blockade on coronary blood flow and CFR in patients with IDC. Fourteen patients with IDC and 10 control subjects underwent time-averaged peak coronary flow velocity (APCFV) measurements (centimeters per second) in the proximal left anterior descending coronary artery at baseline and at maximal hyperemia before and after beta(1) blockade with intravenous esmolol. CFR was defined as APCFV at maximal hyperemia/APCFV at baseline. Although there were no significant differences in APCFV at baseline between patients with IDC and controls, patients with IDC had significantly lower APCFV at maximal hyperemia than controls (54.2 +/- 12.0 vs 75.1 +/- 18.6, p <0.05) and decreased CFR (2.39 +/- 0.38 vs 3.50 +/- 0.54, respectively, p <0.05). After beta(1) blockade, a significant decrease in APCFV at baseline (19.5 +/- 3.7 vs 22.9 +/- 5.0, p <0.05) and enhancement of APCFV at maximal hyperemia (59.5 +/- 13.3 vs 54.2 +/- 12.0, p <0.05) were observed in patients with IDC, but not in control subjects, leading to significant improvement in CFR (3.06 +/- 0.40 vs 2.39 +/- 0.38, p <0.05). In conclusion, patients with IDC had alterations in coronary blood flow and decreased CFR that improved after beta(1) blockade. These alterations in microvascular function, which are partially reversed by beta blockade, may be 1 of the underlying mechanisms that contribute to the improved prognosis of patients with IDC under such therapy.

Drug evaluation: PB-127, a novel contrast agent for the detection of myocardial perfusion.

Point Biomedical Corp is developing PB-127 (CardioSphere) as an ultrasound imaging agent for assessing myocardial perfusion in patients with coronary artery disease. In January 2006, the company submitted an NDA for the agent; this was accepted for review in February 2006, with a Prescription Drug User Fee Act review and action date of late October 2006. PB-127 is effective for intermittent harmonic power Doppler imaging and may be the first contrast agent to receive FDA approval for myocardial perfusion imaging.

Acute coronary syndrome in an adult with anomalous origin of the left anterior descending coronary artery from the pulmonary trunk.

Anomalous origin of the left anterior descending coronary artery is a very rare coronary vascular anomaly, especially in adults. We describe the case of a 45-year-old woman who presented with an acute coronary syndrome. Coronary angiography revealed an anomalous origin of the left anterior descending coronary artery from the main pulmonary trunk, with collateral filling from both the left circumflex and the right coronary artery. Treatment of choice of this coronary anomaly is usually surgical repair, while intense antithrombotic therapy should be considered, especially if the anomalous vessel is ectatic.

Reduced systemic inflammatory response to implantation of sirolimus-eluting stents in patients with stable coronary artery disease.

Stent implantation causes significant injury to the vascular wall, resulting in inflammatory activation. Although sirolimus-eluting stents (SES) have anti-inflammatory properties, their effect on periprocedural systemic inflammatory response has not been sufficiently investigated. Eighty-one patients with stable coronary artery disease involving severe stenosis of one major epicardial coronary artery underwent coronary angioplasty with stent implantation and randomly received either SES or bare metal stents (BMS). Blood samples were taken 24h before, at 24h, 48 h and 1 month after the angioplasty and levels of high sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta), and monocyte chemoattractant protein-1 (MCP-1) were determined. HsCRP after BMS implantation increased over 24h (p<0.001) and then remained steady, as did IL-6 and IL-1 beta similarly. In contrast, their levels in SES patients decreased to below baseline by the end of the month. MCP-1 levels increased by the end of 1 month (p<0.001) in the BMS group, whereas in SES they steadily decreased, becoming significantly lower than baseline from 48 h (p=0.015). In conclusion, patients with SES exhibit an attenuation of the postprocedural systemic inflammatory activation during a 1-month follow-up after stent implantation. This might partially explain the reduced restenosis rate associated with SES.

Effect of inhaled salbutamol on coronary circulation in humans.

In 12 patients we assessed the effect of inhaled salbutamol on the coronary circulation. According to our results, large doses of salbutamol increase coronary flow, but not in proportion to the needs of the myocardium (as documented by the increase in coronary oxygen extraction), and decrease coronary flow reserve. These effects may have deleterious consequences in patients with coronary artery disease, causing or worsening myocardial ischemia.

AI-700 (Acusphere).

Acusphere is developing AI-700, perflubutane-filled synthetic polymer microspheres, for potential use as an ultrasound contrast agent for the assessment of myocardial perfusion. By April 2005, phase III enrollment was expected to be complete by early 2006, and the company expected to file an NDA in the first half of 2006.

Regional coronary flow and contractile reserve in patients with idiopathic dilated cardiomyopathy.

OBJECTIVES: The purpose of this study was to assess regional coronary flow and contractile reserve in patients with idiopathic dilated cardiomyopathy (IDCM). BACKGROUND: Although IDCM has been associated with alterations in coronary blood flow and contractile reserve, little is known about their regional distribution and correlation. METHODS: Fourteen patients with IDCM and 11 control subjects underwent coronary flow velocity (APV) measurements in the left anterior descending (LAD), left circumflex (LCx), and right coronary (RCA) arteries at baseline (b) and at maximal hyperemia (h). Coronary flow reserve (CFR) was defined as h-APV/b-APV. Wall thickening was assessed in 16 segments (7 assigned to LAD, 5 to LCx, and 4 to RCA) both at rest and under peak stress during low-dose dobutamine echocardiography. Regional contractile reserve was defined as the percentage difference in wall motion score index between rest and stress in each vascular territory. RESULTS: Although there were no significant differences in b-APV, patients with IDCM had significantly lower h-APV than controls in all three vascular territories and reduced CFR (LAD: 2.79 +/- 0.43 vs. 3.48 +/- 0.51, p < 0.05; LCx: 2.71 +/- 0.39 vs. 3.36 +/- 0.65, p < 0.05; and RCA: 3.43 +/- 0.55 vs. 4.02 +/- 0.73, p < 0.05). There was also a significant correlation between CFR and the corresponding contractile reserve in the vascular territory of the LAD (r = 0.75, p = 0.002) and the LCx (r = 0.64, p = 0.014). CONCLUSIONS: Patients with IDCM have alterations in regional coronary flow and reduced CFR. Furthermore, the correlation between regional CFR and the corresponding contractile reserve indicates that microvascular dysfunction may have a pathophysiologic role in the evolution of the disease.