Index of microvascular resistance to assess the effect of rosuvastatin on microvascular function in women with chest pain and no obstructive coronary artery disease: A double-blind randomized study.

INTRODUCTION: Many women undergoing coronary angiography for chest pain have no or only minimal coronary artery disease (CAD). However, despite the lack of obstructive CAD, they still have an increased risk of major adverse cardiovascular events. Pleiotropic effects of statins may influence microvascular function, but if statins improve microvascular function in unselected chest pain patients is not well studied. This study assessed microvascular function by using the thermodilution-derived test "the index of microvascular resistance" (IMR) with the aim of determining the (i) IMR level in women with chest pain and non-obstructive CAD and if (ii) IMR is modified by high-dose statin treatment in these patients. Additional objectives were to identify the influence of statins on the health status as assessed with generic health questionnaires and on biomarkers of endothelial activation. MATERIALS AND METHODS: The study was a randomized, double-blind, single-center trial comparing 6 months of rosuvastatin treatment with placebo. In total, 66 women without obstructive CAD were included. Mean age was 52.7 years and 55.5 years in the placebo and rosuvastatin group, respectively. Microvascular function was assessed using the IMR, health status was assessed using the SF-36 and EQ-5D questionnaires, and biochemical values were assessed at baseline and 6 months later. RESULTS AND CONCLUSIONS: In the placebo group IMR was 14.6 (SD 5.7) at baseline and 14.4 (SD 6.5) at follow-up. In the rosuvastatin group IMR was 16.5 (SD 7.5) at baseline and 14.2 (SD 5.8) at follow-up. IMR did not differ significantly between the two study groups at follow-up controlled for preintervention values. C-reactive protein (CRP) was comparable between the groups at baseline, while at follow-up CRP was significantly lower in the rosuvastatin group compared to placebo [0.6 (±0.5) mg/L vs. 2.6 (±3.0) mg/L; p = 0.002]. Whereas rosuvastatin treatment for 6 months attenuated CRP levels, it did not improve microvascular function as assessed by IMR (Clinical Trials.gov NCT01582165, EUDRACT 2011-002630-39.3tcAZ).

Intra-aortic balloon pump in acute chest pain and cardiogenic shock - a long-term follow-up.

Objectives. Coronary revascularisation and intra-aortic balloon pump (IABP) has been considered the gold standard treatment of acute coronary syndrome with cardiogenic shock, recently challenged by the SHOCK II study. The aim of this non-randomised study was to investigate the long term prognosis after immediate IABP supported angiography, in patients with acute chest pain and cardiogenic shock, treated with percutaneous coronary intervention (PCI), cardiac surgery or optimal medical treatment. We assessed data from 281 consecutive patients admitted to our department from 2004 to 2010. Results. Mean (±SD) age was 63.8 ± 11.5 (range 30-84) years with a follow-up of 5.6 ± 4.4 (0-12.7) years. Acute myocardial infarction was the primary diagnosis in 93% of the patients, 4% presented with unstable angina pectoris and 3% cardiomyopathy or arrhythmias of non-ischemic aetiology. Systolic blood pressure at admittance was 85 ± 18 mmHg and diastolic 55 ± 18 mmHg. Thirty day, one- and five-year survival was 71.2%, 67.3% and 57.7%, respectively. PCI was performed immediately in 70%, surgery was done in 17%, and 13% were not eligible for any revascularisation. Independent variables predicting mortality were medical treatment vs revascularisation, out-of-hospital cardiac arrest, and advanced age. Three serious non-fatal complications occurred due to IABP treatment, i.e. 0.001 per treatment day. Conclusions. We report the use of IABP in patients with acute chest pain admitted for angiography. Long-term survival is acceptable and discriminating factors were no revascularisation, out-of-hospital cardiac arrest and age. IABP was safe and feasible and the complication rate was low.

Coronary computed tomography in heart transplant patients: detection of significant stenosis and cardiac allograft vasculopathy, image quality, and radiation dose.

Background Cardiac allograft vasculopathy (CAV) is an accelerated form of atherosclerosis unique to heart transplant (HTX) patients. Purpose To investigate the detection of significant coronary artery stenosis and CAV, determinants of image quality, and the radiation dose in coronary computed tomography angiography (CCTA) of HTX patients with 64-slice multidetector CT (64-MDCT). Material and Methods Fifty-two HTX recipients scheduled for invasive coronary angiography (ICA) were prospectively enrolled and underwent CCTA before ICA with intravascular ultrasound (IVUS). Results Interpretable CCTA images were acquired in 570 (95%) coronary artery segments ≥2 mm in diameter. Sensitivity, specificity, and positive and negative predictive values of CCTA for the detection of segments with significant stenosis (lumen reduction ≥50%) on ICA were 100%, 98%, 7.7%, and 100%, respectively. Twelve significant stenoses were located in segments with uninterpretable image quality or vessel diameter <2 mm; only one was eligible for intervention. IVUS detected CAV (maximal intimal thickness ≥0.5 mm) in 33/41 (81%) patients; CCTA and ICA identified CAV (any wall or luminal irregularity) in 18 (44%) and 14 (34%) of these 33 patients, respectively. The mean estimated radiation dose was 19.0 ± 3.4 mSv for CCTA and 5.7 ± 3.3 mSv for ICA ( P < 0.001). Conclusion CCTA with interpretable image quality had a high negative predictive value for ruling out significant stenoses suitable for intervention. The modest detection of CAV by CCTA implied a limited value in identifying subtle CAV. The high estimated radiation dose for 64-MDCT is of concern considering the need for repetitive examinations in the HTX population.

Comparison of simplified and comprehensive methods for assessing the index of microvascular resistance in heart transplant recipients.

OBJECTIVES: The objectives of the present study were to compare a simplified and a comprehensive method of estimating the index of microvascular resistance (IMR) and assess the changes from 7-11 weeks to 1 year after heart transplant (HTx). BACKGROUND: he IMR is specific to the microvasculature and reflects the status of the microcirculation in cardiac patients and can be estimated via a simplified method (IMR(s)) or a comprehensive method (IMR(c)). The calculation for the latter includes coronary wedge pressure and central venous pressure. METHODS: Consecutively transplanted patients (n = 48) underwent left and right heart catheterization including physiological evaluation at two time points post-HTx. The agreement between the values of IMR obtained using the IMR(s) and IMR(c) methods were assessed using Bland-Altman analysis. The agreements and differences were assessed using mixed model analysis. RESULTS: The mean bias between IMRs and IMRc was 1.3 mm Hg·s (95% limits of agreement: -1.2, 3.8 mm Hg). Between 7-11 weeks and 1 year post-HTx there was a significant decline in IMR(s) values (P = 0.03) but a smaller and statistically nonsignificant decline in IMR(c) values (P = 0.13). The significant difference (P = 0.04) between IMR(c) and IMR(s) 7-11 weeks post-HTx was no longer present at 1 year (P = 0.24). CONCLUSIONS: The IMR(s) method resulted in slightly higher IMR estimates and exhibited a somewhat larger change over the 10-month follow-up period than the IMR(c) method. However, the differences between the methods were small and unlikely to be of clinical importance.

Rosuvastatin alters the genetic composition of the human gut microbiome.

The gut microbiome contributes to the variation of blood lipid levels, and secondary bile acids are associated with the effect of statins. Yet, our knowledge of how statins, one of our most common drug groups, affect the human microbiome is scarce. We aimed to characterize the effect of rosuvastatin on gut microbiome composition and inferred genetic content in stool samples from a randomized controlled trial (n = 66). No taxa were significantly altered by rosuvastatin during the study. However, rosuvastatin-treated participants showed a reduction in the collective genetic potential to transport and metabolize precursors of the pro-atherogenic metabolite trimethylamine-N-oxide (TMAO, p < 0.01), and an increase of related metabolites betaine and γ-butyrobetaine in plasma (p < 0.01). Exploratory analyses in the rosuvastatin group showed that participants with the least favorable treatment response (defined as < median change in high-density/low-density lipoprotein (HDL/LDL) ratio) showed a marked increase in TMAO-levels compared to those with a more favorable response (p < 0.05). Our data suggest that while rosuvastatin has a limited effect on gut microbiome composition, it could exert broader collective effects on the microbiome relevant to their function, providing a rationale for further studies of the influence of statins on the gut microbiome.

Mechanisms of preejection and postejection velocity spikes in left ventricular myocardium: interaction between wall deformation and valve events.

BACKGROUND: Normal left ventricular myocardium demonstrates distinct spikes in the velocity trace before and after left ventricular ejection. We tested the hypothesis that the preejection and postejection velocity spikes reflect early systolic shortening and late systolic lengthening that are interrupted by mitral and aortic valve closure, respectively. METHODS AND RESULTS: In 11 anesthetized dogs, timing of valve closure was determined by pressure variables; left ventricular dimensions were determined by sonomicrometry. Myocardial shortening started 20+/-10 ms (mean+/-SD; P<0.001) before mitral valve closure and was interrupted at the time of mitral valve closure (time difference, 4+/-7 ms). Similarly, myocardial lengthening started 31+/-15 ms (P<0.001) before aortic valve closure and was interrupted at the time of aortic valve closure (time difference, 0+/-3 ms). Prevention of mitral (n=4) and aortic (n=4) valve closure by stenting the valves abolished the preejection and postejection velocity spikes, respectively. Echocardiographic measurements of patients (n=15) with severe mitral regurgitation showed that the preejection velocity spike was reduced after prosthetic valve replacement (43+/-25 versus 32+/-15 mm/s; P=0.036), indicating that preejection shortening was larger with a leaking valve. Similarly, late systolic lengthening was reduced in patients (n=15) with severe aortic regurgitation after prosthetic valve replacement; minimum postejection velocity spike was increased from -32+/-11 to -17+/-11 mm/s; P=0.0003). Asynchronous onset of contraction/relaxation and atrioventricular interaction were investigated as alternative mechanisms of the velocity spikes in dogs and patient groups but were found implausible. CONCLUSIONS: This study supports the hypothesis that normal left ventricular preejection and postejection velocity spikes are attributed to valve closures that interrupt early systolic shortening and late systolic lengthening, respectively.

Intracoronary injection of mononuclear bone marrow cells in acute myocardial infarction.

BACKGROUND: Previous studies have shown improvement in left ventricular function after intracoronary injection of autologous cells derived from bone marrow (BMC) in the acute phase of myocardial infarction. We designed a randomized, controlled trial to further investigate the effects of this treatment. METHODS: Patients with acute ST-elevation myocardial infarction of the anterior wall treated with percutaneous coronary intervention were randomly assigned to the group that underwent intracoronary injection of autologous mononuclear BMC or to the control group, in which neither aspiration nor sham injection was performed. Left ventricular function was assessed with the use of electrocardiogram-gated single-photon-emission computed tomography (SPECT) and echocardiography at baseline and magnetic resonance imaging (MRI) 2 to 3 weeks after the infarction. These procedures were repeated 6 months after the infarction. End points were changes in the left ventricular ejection fraction (LVEF), end-diastolic volume, and infarct size. RESULTS: Of the 50 patients assigned to treatment with mononuclear BMC, 47 underwent intracoronary injection of the cells at a median of 6 days after myocardial infarction. There were 50 patients in the control group. The mean (+/-SD) change in LVEF, measured with the use of SPECT, between baseline and 6 months after infarction for all patients was 7.6+/-10.4 percentage points. The effect of BMC treatment on the change in LVEF was an increase of 0.6 percentage point (95% confidence interval [CI], -3.4 to 4.6; P=0.77) on SPECT, an increase of 0.6 percentage point (95% CI, -2.6 to 3.8; P=0.70) on echocardiography, and a decrease of 3.0 percentage points (95% CI, 0.1 to -6.1; P=0.054) on MRI. The two groups did not differ significantly in changes in left ventricular end-diastolic volume or infarct size and had similar rates of adverse events. CONCLUSIONS: With the methods used, we found no effects of intracoronary injection of autologous mononuclear BMC on global left ventricular function.

The tumour necrosis factor superfamily ligand APRIL (TNFSF13) is released upon platelet activation and expressed in atherosclerosis.

Activated platelets release a wide range of inflammatory mediators, including members of the tumour necrosis factor (TNF) superfamily (e.g. CD40 ligand [CD40L] and LIGHT). Such platelet-mediated inflammation could be involved in atherogenesis and plaque destabilisation. In the present study we investigated whether APRIL, another member of the TNF superfamily that has been detected in megakaryocytes, could be released from platelets upon activation. The release of APRIL was studied in thrombin receptor (SFLLRN) activated platelets, and the expression of APRIL was examined in plasma and within the atherosclerotic lesion in patients with carotid and coronary atherosclerosis. Upon SFLLRN activation, there was a gradual release of APRIL, reaching maximum after 90 minutes. While this pattern is similar to that of CD40L and LIGHT, the release of APRIL was quite differently regulated. Thus, prostaglandin E1, but not inhibitors of metal-dependent proteases and actin polymerisation or the lack of GP IIb/IIIa, blocks APRIL release in activated platelets. With relevance to atherogenesis, we found that patients with coronary artery disease (n=80) had raised plasma levels of APRIL as compared with controls (n=20), and APRIL immunoreactivity was detected in aggregated platelets within the ruptured plaque in patients with myocardial infarction and within macrophages in symptomatic carotid plaques. In conclusion, activated platelets release significant amounts of APRIL in a long-lasting manner, differently regulated than the gradual release of other platelet-derived TNF superfamily ligands. The enhanced expression of APRIL in atherosclerotic disorders, both systemically and within the lesion, may suggest a potential involvement of APRIL in atherogenesis.

Echocardiographic evidence of right ventricular functional improvement after balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) induces right ventricular (RV) adaptive changes but often results in RV failure and death. Balloon pulmonary angioplasty (BPA) is a treatment option in patients in whom pulmonary endarterectomy is contraindicated and in patients with residual pulmonary hypertension after pulmonary endarterectomy. We hypothesized that RV reverse remodeling and improved RV function would occur after BPA in patients with CTEPH. METHODS: In 26 patients with CTEPH (59 ± 12 years old; 11 men), echocardiography, cardiopulmonary exercise testing, blood samples, and right-sided cardiac catheterization were performed before and after 4 ± 2 BPA procedures. Echocardiography images were analyzed off-line with particular focus on RV function according to current recommendations. Differences from baseline to follow-up were analyzed by paired samples t tests. RESULTS: Significant improvements in hemodynamics, peak oxygen consumption, and levels of N-terminal pro-B-type natriuretic peptide were detected after BPA. All measures of RV function improved considerably, including fractional area change (+6%; p = 0.003), tricuspid annular plane systolic excursion (+3 mm; p < 0.001), and RV free wall peak strain (-4.4; p = 0.002). RV end-diastolic diameter, area, and free wall thickness decreased significantly, whereas left ventricular diameter and stroke volume increased. CONCLUSIONS: After BPA, a significant improvement in RV functional parameters could be observed by echocardiography, adding credibility to this form of treatment in patients with CTEPH.

Index of microvascular resistance after early conversion from calcineurin inhibitor to everolimus in heart transplantation: A sub-study to a 1-year randomized trial.

BACKGROUND: Microvascular function in transplanted hearts can be evaluated by methods used in routine left heart catheterization follow-up after heart transplantation (HTx). This sub-study of a randomized study compared the effects of everolimus (EVR) and calcineurin inhibitor (CNI) treatment on microvascular function as expressed by the index of microvascular resistance (IMR) at 1 year after HTx. A secondary objective was to compare the change in IMR from 7-11 weeks to 1 year after HTx between randomized groups. METHODS: There were 70 HTx recipients included and randomly assigned to combination therapy (EVR and CNI with early CNI withdrawal) vs conventional CNI treatment. Coronary physiologic assessment was performed 7-11 weeks and 1 year after HTx. A linear mixed model was used to assess the group difference at 1 year and the difference in IMR change between 7-11 weeks and 1 year after HTx. RESULTS: At 1 year, there was no significant difference in IMR between the EVR group (17.5 mm Hg∙sec ± 8.9) (mean ± SD) and the CNI group (14.9 mm Hg∙sec ± 6.6, p = 0.17). The difference in IMR change between the 2 treatment arms was 1.6 mm Hg∙sec (95% confidence interval, -2.8 to 5.9; p = 0.49). Spearman's rank correlation coefficient at 1 year after HTx between IMR and maximal intimal thickness as assessed with intravascular ultrasound in the left anterior descending artery was -0.13 (p = 0.28). CONCLUSIONS: In this prospective, open, randomized study comparing early CNI withdrawal with mammalian target of rapamycin inhibitors immunosuppression during the first year after HTx, early transition from CNI-based immunosuppression to EVR-based treatment did not result in differences in microvascular function as assessed by the IMR.

Standardized angiographically guided over-dilatation of stents using high pressure technique optimize results without increasing risks.

BACKGROUND: Routine angio-guided stent deployment results in a relatively high restenosis rate, which is mostly due to stent sub-expansion. Several different intravascular ultrasound (IVUS) criteria for optimal stent deployment have been proposed. A minimal in-stent restenosis and a minimal in-stent lumen area of > or = 9 mm2 have been associated with low rates of restenosis and target lesion revascularization (TLR) at 6 months. The role of high-pressure stent deployment and/or upsizing the post-dilatation balloon has not yet been clarified. The aim of this study was to evaluate the possibility of achieving accepted IVUS criteria safely without IVUS guidance with the combination of high-pressure deployment and post-dilatation with a 0.25 mm oversized balloon. METHODS: Thirty-four stents (26 NIR, 3 AVE GFX, 3 ACS GFX, 1 Bard, 1 Jostent) were implanted in 30 patients until optimal angiographical results were obtained (< 10% residual stenosis visually). Forty percent of the patients had unstable angina pectoris, forty-four percent had complex lesions (B2 and C) and 29% were occlusions. Mean inflation pressure was 12.6 +/- 1.6 atm, mean stent diameter was 3.2+/- 0.4 mm and mean stent length was 15.1+/- 5.4 mm. Post-dilatation was performed with the same stent using a short (compared to the angiographic reference segment), 0.25 mm oversized Scimed Maxxum Energy 3.5 +/- 0.4 mm balloon using high pressure (16.1 +/- 1.7 atm) followed by an off-line IVUS examination of the stents. There was clinical follow-up for 1 year. Results in patients with single-vessel disease were compared with those of non-randomized controls, who were stented with high pressure but without over-dilatation. RESULTS: No stent achieved the nominal diameter, in spite of over-dilatation. Mean minimal stent diameter (MLD) according to IVUS was 2.9 +/- 0.4 mm (92% of the angiographic reference diameter). Mean minimal lumen area (MLA) was 7.7 +/- 2.2 mm2. An in-stent MLA > or = 90% of the distal reference segment (AVID criteria) and an MLA > or = 100% or > or = 90% of the smallest/average reference segment (MUSIC criteria) was found in 67% and 57%, respectively. MLA > or = 9 mm2 was achieved in 38%. All stents had good apposition and obtained a symmetry index > or = 0.7 mm. No acute perforations, dissections or other serious complications occurred during the over-dilatation. At 1 year, five patients had re-angina leading to a new coronary angiography; only 1 patient had a significant in-stent restenosis requiring re-PTCA. Compared to non-overdilated historical controls, the standardized over-dilatation seemed to give a larger MLD (3.0 +/- 0.4 mm vs. 2.7 +/- 0.4 mm; p = 0.03), more patients who fulfilled AVID criteria (70% vs. 32%; p = 0.048) and more stents with MLA > or = 9 mm2 (46% vs. 11%; p = 0.02). CONCLUSION: A standardized 0.25 mm over-dilatation of stents never achieved nominal stent size, but did improve lumen gain and was associated with low target vessel revascularization without adding complications to the routine stenting procedure.

Reference interval for the index of coronary microvascular resistance.

AIMS: The index of microvascular resistance (IMR) is a relatively new tool that is used to assess microvascular function during routinely performed left heart catheterisations. In order to establish a reference interval for IMR, we investigated a subset of arrhythmia patients with structurally normal hearts and no or minimal coronary artery disease. METHODS AND RESULTS: Physiological variables, including IMR, were measured in 20 otherwise healthy patients aged 40-60 years (10 males and 10 females) who had been referred for electrophysiological evaluation of suspected atrioventricular nodal re-entry tachycardia. IMR values were non-normally distributed with a median value of 12.6. We established a reference interval, that would be relevant to 95% of the population, of 7.3 (90% CI: 6.6-8.0) - 27.2 (90% CI: 20.8-33.7), using Box-Cox transformation and the robust Horn method. Spearman's rank correlation analysis revealed no significant relationship between IMR and several different variables. CONCLUSIONS: A reference interval for IMR was established in a population of patients aged 40-60 years with structurally normal hearts, considered to be representative of the general population. IMR was not related to sex, age or any of the other variables tested, suggesting that this reference range can be applied to the general population.

Balloon pulmonary angioplasty in patients with inoperable chronic thromboembolic pulmonary hypertension.

OBJECTIVE: To examine the effect of balloon pulmonary angioplasty (BPA) on chronic thromboembolic pulmonary hypertension (CTEPH) in patients with inoperable disease or persistent pulmonary hypertension after pulmonary endarterectomy. DESIGN: Observational cohort study. SETTING: Referred patients with inoperable or persistent CTEPH. PATIENTS: Twenty consecutive CTEPH patients (10 females), aged 60±10 years. INTERVENTIONS BPA MAIN OUTCOME MEASURES: Right heart catheterisation, functional capacity (cardiopulmonary exercise testing (CPET) and NYHA class) and blood sampled biomarkers N-terminal pro-brain natriuretic peptide (NT-proBNP) and troponin T examined at the time of diagnosis and repeated in all patients 3 months after the last BPA. RESULTS: Seventy-three catheterisations were performed with 18.6±6.1 BPAs per patient on segmental and subsegmental arteries. Two deaths occurred following the first BPA, with an overall 10% periprocedural death rate. Reperfusion oedema complicated seven procedures. Comparisons before and after BPA showed significant haemodynamic improvements, including decreased mean pulmonary artery pressure (mPAP) (45±11 mm Hg vs 33±10 mm Hg; p<0.001) and increased cardiac output (4.9±1.6 L/min vs 5.4±1.9 L/min; p=0.011). Reduced right ventricular strain was indicated by significantly lower plasma levels of NT-proBNP and troponin T. Significant improvement in functional capacity was evident as assessed by NYHA class (3.0±0.5 vs 2.0±0.5; p<0.001) and CPET (13.6±5.6 mL/kg/min vs 17.0±6.5 mL/kg/min; p<0.001). Seventeen patients (85%) were alive after 51±30 months of follow-up. CONCLUSIONS: BPA may offer an alternative form of treatment in selected CTEPH patients. While prognostic markers such as haemodynamics, functional capacity and biomarkers improve, significant periprocedural complications must be recognised. Randomised trials are warranted.