Alberto Ranieri De Caterina

Reversible coronary microvascular dysfunction: a common pathogenetic mechanism in Apical Ballooning or Tako-Tsubo Syndrome

AIMS To study coronary microvascular dysfunction as possible pathogenetic mechanism in Apical Ballooning Syndrome (ABS). METHODS AND RESULTS Fifteen ABS patients (all women, 68 +/- 14 years) underwent myocardial contrast echocardiography at baseline during adenosine infusion (140 microg/kg/min) and at 1-month follow-up and compared with a group of anterior ST-elevation myocardial infarction (STEMI) patients with similar clinical characteristics. Myocardial perfusion was assessed by contrast score index (CSI) and endocardial length of contrast defect (contrast defect length, CDL), whereas myocardial dysfunction by wall motion score index (WMSI), endocardial length of contractile dysfunction (wall motion defect length, WMDL), and LV ejection fraction (LVEF). At baseline, no difference in myocardial perfusion and dysfunction were present between the two groups. During adenosine challenge, while no changes were observed in STEMI group, in ABS patients CSI, CDL, WMSI, and WMDL significantly decreased compared with baseline (P < 0.001 vs. baseline for all parameters) and LVEF significantly increased (P = 0.01 vs. baseline). At 1-month follow-up, myocardial perfusion and dysfunction completely recovered in ABS patients (P < 0.001 vs. baseline for all parameters), whereas no significant changes were observed in STEMI group. CONCLUSION Our data strongly suggest that in ABS, irrespectively of its underlying aetiology, acute and reversible coronary microvascular vasoconstriction could represent a common pathophysiological mechanism.

Maximal hyperemia in the assessment of fractional flow reserve: intracoronary adenosine versus intracoronary sodium nitroprusside versus intravenous adenosine: the NASCI (Nitroprussiato versus Adenosina nelle Stenosi Coronariche Intermedie) study.

OBJECTIVES This study sought to compare increasing doses of intracoronary (i.c.) adenosine or i.c. sodium nitroprusside versus intravenous (i.v.) adenosine for fractional flow reserve (FFR) assessment. BACKGROUND Maximal hyperemia is the critical prerequisite for FFR assessment. Despite i.v. adenosine currently representing the recommended approach, i.c. administration of adenosine or other coronary vasodilators constitutes a valuable alternative in everyday practice. However, it is surprisingly unclear which i.c. strategy allows the achievement of FFR values comparable to i.v. adenosine. METHODS Fifty intermediate coronary stenoses (n = 45) undergoing FFR measurement were prospectively and consecutively enrolled. Hyperemia was sequentially induced by incremental boli of i.c. adenosine (ADN) (60 μg ADN60, 300 μg ADN300, 600 μg ADN600), by i.c. sodium nitroprusside (NTP) (0.6 μg/kg bolus) and by i.v. adenosine infusion (IVADN) (140 μg/kg/min). FFR values, symptoms, and development of atrioventricular block were recorded. RESULTS Incremental doses of i.c. adenosine and NTP were well tolerated and associated with fewer symptoms than IVADN. Intracoronary adenosine doses (0.881 ± 0.067, 0.871 ± 0.068, and 0.868 ± 0.070 with ADN60, ADN300, and ADN600, respectively) and NTP (0.892 ± 0.072) induced a significant decrease of FFR compared with baseline levels (p < 0.001). Notably, ADN600 only was associated with FFR values similar to IVADN (0.867 ± 0.072, p = 0.28). Among the 10 patients with FFR values ≤0.80 with IVADN, 5 were correctly identified also by ADN60, 6 by ADN300, 7 by ADN600, and 6 by NTP. CONCLUSIONS Intracoronary adenosine, at doses higher than currently suggested, allows obtaining FFR values similar to i.v. adenosine. Intravenous adenosine, which remains the gold standard, might thus be reserved for those lesions with equivocal FFR values after high (up to 600 μg) i.c. adenosine doses.

Paradoxical preservation of vascular function in severe obesity

BACKGROUND Obesity is associated with a high risk of coronary artery disease morbidity and mortality. Yet, postmortem studies have shown that severely obese subjects exhibit smooth coronary arteries, thus suggesting that they may be protected from atherosclerosis. We assessed vascular function and its possible determinants in a cohort of normal-weight to severely obese insulin-sensitive subjects (body mass index [BMI] 23.2-49 kg/m(2)). METHODS Seventy-one healthy, insulin-sensitive subjects (Homeostasis Model Assessment of Insulin Resistance index <2.5), divided into normal-weight (n = 13; BMI = 23.2 +/- 1.6), obese (n = 35; BMI=32.6+/-2.5), and severely obese (n=23; BMI=49.0+/-7.9) groups, were enrolled. Vascular function was evaluated by flow-mediated dilation and carotid intima-media thickness. High-sensitivity C-reactive protein, leptin, adiponectin, vascular growth factors, and CD34+KDR+/CD133+ endothelial progenitor cells, known markers of vascular health/protection, also were measured. RESULTS Flow-mediated dilation was higher in severely obese than in obese and normal-weight individuals (P=.019 and P=.011 respectively). Intima-media thickness was consistently lower in severely obese than in obese individuals (P=.040) and similar in severely obese and normal-weight individuals (P >.99). Levels of high-sensitivity C-reactive protein and leptin were higher in severely obese than in obese and normal-weight individuals (high-sensitivity C-reactive protein: P=.018 and P=.05, respectively; leptin: P <.001 for both comparisons). CD34+KDR+ endothelial progenitor cells were significantly higher in severely obese versus obese individuals (P=.039). CONCLUSION Our study demonstrates that vascular function is paradoxically better in severely obese than in obese subjects and similar to that found in normal-weight subjects. Despite higher levels of high-sensitivity C-reactive protein and leptin, severely obese individuals may be partially protected from atherosclerosis, possibly by a greater mobilization of endothelial progenitor cells.

Influence of the Amount of Myocardium Subtended by a Stenosis on Fractional Flow Reserve

Background—Fractional flow reserve (FFR) specifically relates to the severity of a stenosis to the mass of tissue to be perfused. Accordingly, the larger the territory to be perfused, the greater the flow and the pressure gradient induced by maximal hyperemia. Although this notion may be considered intuitive, its unequivocal demonstration is still lacking. The aim of our study was to evaluate the influence of the amount of myocardium subtended to an intermediate stenosis on FFR, especially in relation to quantitative coronary angiography. Methods and Results—The severity of each lesion was assessed by FFR and 2-dimensional quantitative coronary angiography. The amount of jeopardized myocardium was evaluated using 3 validated scores specifically adapted to this aim: the Duke Jeopardy Score (DJS), the Myocardial Jeopardy Index (MJI), and the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) Lesion Score (ALS). The presence of a concomitant collateralized chronic total occlusion was also reported. A total of 213 intermediate coronary stenoses in 184 patients were enrolled. FFR values were correlated to minimal lumen diameter (r=0.34; P<0.0001) and diameter stenosis (r=−0.28; P<0.0001). FFR was inversely correlated with DJS, MJI, and ALS (r=−0.28, P<0.0001; r=−0.40, P<0.0001; and r=−0.34, P<0.0001). Lesions localized on proximal left anterior descending were related to significantly lower FFR values and to a higher rate of a positive FFR compared with those in distal left anterior descending, left circumflex, and right coronary arteries (0.80±0.09 versus 0.84±0.08 versus 0.88±0.09 versus 0.91±0.04; P<0.0001). The presence of a collateralized chronic total occlusion was associated with significantly lower FFR values (0.80±0.07 versus 0.85±0.09; P<0.005). At multivariate analysis MJI, minimal lumen diameter, and presence of a collateralized chronic total occlusion were confirmed as significant predictors of FFR. Conclusions—A larger amount of perfused myocardium subtended by a stenosis is associated with a higher probability that an angiographically intermediate coronary stenosis is functionally significant.

Efficacy of contrast medium induced Pd/Pa ratio in predicting functional significance of intermediate coronary artery stenosis assessed by fractional flow reserve: insights from the RINASCI study.

AIMS The need of adenosine administration for the achievement of maximal hyperaemia limits the widespread application of fractional flow reserve (FFR) in the real world. We hypothesised that Pd/Pa ratio registered during submaximal reactive hyperaemia induced by conventional non-ionic radiographic contrast medium (contrast medium induced Pd/Pa ratio: CMR) can be sufficient for the assessment of physiological severity of stenosis in the vast majority of cases. The aim of the present study was to test the accuracy of CMR in comparison to FFR. METHODS AND RESULTS Eighty patients with 104 intermediate coronary stenoses were prospectively and consecutively enrolled. CMR was obtained after intracoronary injection of 6 ml of radiographic contrast medium, while FFR was measured after administration of adenosine. Despite the fact that CMR values were significantly higher than FFR values (0.88 [IR 0.80-0.92] vs. 0.87 [IR 0.83-0.94], p<0.001), a strong correlation between CMR and FFR values was observed (r=0.94, p<0.001) with a close agreement at Bland-Altman analysis (95% CI of disagreement: -0.029 to 0.072). ROC curve analysis showed an excellent accuracy of CMR cut-off of ≤0.83 in predicting FFR value ≤0.80 (AUC 0.97 [95% CI: 0.91-0.99, specificity 96.1, sensitivity 85.7]). Moreover, no FFR value ≤0.80 corresponded to a CMR ≥0.88. CONCLUSIONS CMR is accurate in predicting the functional significance of coronary stenosis. This could allow limiting the use of adenosine to obtain FFR to doubtful cases. In particular, we suggest considering a CMR value ≤0.83 to be significant, a CMR value ≥0.88 as not significant, and inducing maximal hyperaemia using adenosine for FFR assessment when CMR is between 0.84 and 0.87.

The role of Beta-blockers as first-line therapy in hypertension.

National and international guidelines still recommend β-blockers (BBs) as first-line agents in uncomplicated prevention of hypertension. However, it has been shown that BBs reduce blood pressure less than other drugs, specifically with regard to central aortic pressure. More importantly, recent meta-analyses have highlighted that in primary prevention BBs are associated with a relatively weak effect in reducing stroke compared to placebo or no treatment and, compared with other drugs, show evidence of a worse cardiovascular outcome. Several reasons might explain their mild cardioprotective effect, such as their unfavorable metabolic properties, a lack of efficacy on left ventricular hypertrophy regression and endothelial dysfunction, and reduced patient compliance. Thus, the available evidence does not support the use of BBs as first-line drugs in the treatment of uncomplicated hypertension. It remains to be determined whether newer BBs, such as nebivolol and carvedilol, will be more effective than older compounds in improving cardiovascular prognosis.

Characterization of microvascular and myocardial damage within perfusion defect area at myocardial contrast echocardiography in the subacute phase of myocardial infarction

AIMS The anatomical correlates of perfusion defect (PD) at myocardial contrast echocardiography (MCE) in the subacute phase of ST-elevation myocardial infarction (STEMI) are currently unknown. The study aimed at assessing whether, in the subacute phase of STEMI, within MCE PD microvessels are anatomically damaged or if some vasodilation can be still elicited and if the PD correlates with the extent of myocardial necrosis. METHODS AND RESULTS Twenty-two post-percutaneous coronary intervention (PCI) patients underwent MCE 7 ± 1 days after STEMI, at baseline and after adenosine (ADN) administration. An area of completely non-opacified myocardium, corresponding to the area of the PD, was quantitated by planimetry. The area of the PD on MCE was compared with biochemical and imaging measures of myocardial necrosis: cardiac Troponin T peak (cTnT peak) and hyperenhanced area at gadolinium-enhanced cardiac magnetic resonance (Gd-CMR), respectively. After vasodilator stimulus, the area of the PD remained significantly unchanged when compared with the baseline value (P = 0.09 vs. baseline). The MCE index correlated at baseline with cTnT peak and Gd-CMR assessments of myocardial necrosis (P < 0.001). Also after ADN infusion, correlations between PD and extent of myocardial necrosis were similar to that assessed at baseline. CONCLUSION When assessed in the subacute phase of STEMI, the extent of the PD on MCE represents an area of both myocardial and microvascular necrosis.

Effects of late REopening of Coronary total Occlusion on micRovascular perfusion and myocarDial function: the RECORD study

AIMS The effects of the reopening of a coronary total occlusion (CoTO) on microvascular perfusion in subacute or chronic coronary syndromes are actually unclear. We aimed at evaluating the microvascular perfusion pattern by myocardial contrast echocardiography (MCE), in addition to contractile function, before and after CoTO reopening. METHODS Twenty four patients with subacute and chronic coronary syndromes and CoTO datable >7 days underwent evaluation of microvascular perfusion and left ventricular (LV) function by MCE (Acuson Sequoia, with Sonovue, Bracco) before the reopening of the CoTO and at 9 ± 3 months of follow-up. Microvascular perfusion was semi-quantitatively assessed by the contrast score index (CSI), whereas the endocardial length of the perfusion defect [contrast defect length (CDL)], measured in three apical views and averaged, was expressed as a percentage of the total LV endocardial border. The wall motion score index (WMSI), LV volumes, and ejection fraction were also calculated. RESULTS At baseline, a mild impairment of LV contractile function was observed, which corresponded to a similar impairment of the coronary microvascular perfusion in the overall study population. At follow-up, a significant reduction of CDL% [8.23 (0-19.63) vs. 0 (0-3.68), P = 0.005], improvement of the CSI (1.41 ± 0.29 vs. 1.12 ± 0.17, P = 0.001) and the WMSI (1.73 ± 0.41 vs. 1.33 ± 0.34, P = 0.0004), and increase in the ejection fraction (47.48% ± 8.66 vs. 55.60% ± 8.29, P = 0.0001) were found. CONCLUSION Reopening of a CoTO in patients with clinical indications to myocardial revascularization is associated with the improvement of coronary microvascular perfusion and the recovery of contractile function.

Limitations of noninvasive measurement of fractional flow reserve from coronary computed tomography angiography.

We read with interest the paper by Koo et al. ([1][1]) regarding the diagnostic accuracy of noninvasive measurement of fractional flow reserve (FFR) from coronary computed tomography angiography data (FFRCT). We do recognize the potential clinical and economic relevance of the validation of a

Statins Reduce Incidence of Early Perioperative Complications and Length of in-Hospital Stay after Coronary Artery Bypass Graft Surgery

Background: Coronary artery bypass grafting (CABG) is associated with several perioperative complications that may significantly prolong length of in-hospital stay, increase costs and provide worse long term outcome. The 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors, or statins, exert anti-inflammatory and vascular protective effects. We hypothesized that pre-operatory statin therapy may reduce incidence of early perioperative complications and length of in-hospital stay following CABG.Methods: We retrospectively enrolled 103 patients (age 67±3; 18 females), who underwent CABG. Patients were allocated into 2 groups: 57 patients on statin therapy prior to CABG (St Group) and 46 patients not on statin therapy (n-St group). Demographic and clinical features, pre-operative medications use and the incidence of early adverse postoperative events were collected. Pre-operative risk of death using the European System for Cardiac Operative Risk Evaluation (EuroSCORE) was also calculated. The primary end-point was the composite of early complications occurring after surgery, including infections, bleedings, sustained ventricular and supra-ventricular tachyarrhythmias, cardiogenic shock, myocardial infarction and mortality. As secondary end-points single perioperative complications were considered. In-hospital stay length was also evaluated.Results: Clinical features, cholesterol levels and EuroSCORE were similar between two groups. Statin therapy and EuroSCORE emerged as predictors of the composite adverse outcome. n-St patients had a significant higher rate of early complications if compared with St patients: the primary endpoint occurred in 18 St patients (31%) versus 25 (54%) non-St patients (p=0.019). Multivariate analysis confirmed pre-operative statin therapy and EuroSCORE as independent predictors of the primary endpoint (OR=0.307, 95% CI=0.123-0.766, p=0.011 and OR= 2.114, 95% CI= 1.213- 4.407, p= 0.002 respectively) showing a protective role of the statin therapy.The incidence of secondary end-points did not differ significantly between the groups, while in-hospital stay was longer in n-St group if compared with St group (7.7±3,9 days vs 5,6±1,8 days; p=0,001).Conclusion: Our data suggest that statin therapy may reduce early perioperative complications after coronary artery bypass grafting. This effect is independent from cholesterol basal levels, thus supporting pre-operative statin use in patients undergoing CABG.