LiDAR GEDI derived tree canopy height heterogeneity reveals patterns of biodiversity in forest ecosystems.

The "Height Variation Hypothesis" is an indirect approach used to estimate forest biodiversity through remote sensing data, stating that greater tree height heterogeneity (HH) measured by CHM LiDAR data indicates higher forest structure complexity and tree species diversity. This approach has traditionally been analyzed using only airborne LiDAR data, which limits its application to the availability of the dedicated flight campaigns. In this study we analyzed the relationship between tree species diversity and HH, calculated with four different heterogeneity indices using two freely available CHMs derived from the new space-borne GEDI LiDAR data. The first, with a spatial resolution of 30 m, was produced through a regression tree machine learning algorithm integrating GEDI LiDAR data and Landsat optical information. The second, with a spatial resolution of 10 m, was created using Sentinel-2 images and a deep learning convolutional neural network. We tested this approach separately in 30 forest plots situated in the northern Italian Alps, in 100 plots in the forested area of Traunstein (Germany) and successively in all the 130 plots through a cross-validation analysis. Forest density information was also included as influencing factor in a multiple regression analysis. Our results show that the GEDI CHMs can be used to assess biodiversity patterns in forest ecosystems through the estimation of the HH that is correlated to the tree species diversity. However, the results also indicate that this method is influenced by different factors including the GEDI CHMs dataset of choice and their related spatial resolution, the heterogeneity indices used to calculate the HH and the forest density. Our finding suggest that GEDI LIDAR data can be a valuable tool in the estimation of forest tree heterogeneity and related tree species diversity in forest ecosystems, which can aid in global biodiversity estimation.

Understanding the economic impact of intravascular ultrasound (IVUS).

AIMS: To examine the cost-effectiveness of intravascular ultrasound (IVUS) use during percutaneous coronary intervention (PCI) with drug-eluting stents (DES) in treating coronary artery disease (CAD). METHODS AND RESULTS: A Markov model was constructed with a lifetime horizon to compare costs and health outcomes between IVUS-guided PCI and PCI guided solely by angiography from an Italian healthcare payer perspective. The population examined included CAD patients undergoing PCI with DES. From a healthcare payer perspective, the resulting incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year was negative in the base-case scenario (i.e., IVUS benefit assumed to persist beyond the first year). When IVUS benefit was assumed to be limited to the first year, the ICER increased to €9,624. This conclusion remained consistent even when scenarios varied regarding the duration of the device's effect. Furthermore, benefits of using IVUS were greater for patients with acute coronary syndrome, renal insufficiency, and diabetes. CONCLUSIONS: Using IVUS with angiography is a dominant strategy in Italy, and results demonstrate that it is desirable to target those at a greater risk of restenosis (i.e., patients with diabetes, chronic kidney disease, and acute coronary syndrome), who tend to benefit more from accurate stent implantation. Further information is necessary regarding the long-term benefits of IVUS, however sensitivity analysis presented in this research demonstrates a strong argument supporting the cost-effectiveness of IVUS.

RESTEM: a percutaneous coronary intervention 'real world' registry in the drug-eluting stent era.

Sirolimus-eluting stents (SESs) reduce the rate of in-stent restenosis in selected cases. Their performance in more complex patients and their impact on the final clinical outcome of these patients, however, remains uncertain. RESTEM Registry (REgistro delle PCI in era di STEnt Medicati), a prospective multicenter registry collecting all percutaneous coronary interventions (PCIs) performed over 20 months and monitored up to 2 years, includes 5524 consecutive patients treated with bare metal stent (BMS) (72%), sirolimus-eluting stent (SES) (15%), combined BMS+SES (4%), or other techniques (9%). The combination of death, acute myocardial infarction (AMI), unstable angina and revascularizations had been chosen as primary endpoint. One-year multivariate analysis shows no significant advantage of SES in combined clinical events, a slight benefit in primary endpoint [18.5 vs. 25.0% BMS=odds ratio (OR) 0.78) and revascularizations (13.6 vs. 20.4% BMS=OR 0.74], a consistent advantage when only target vessel revascularizations (TVRs) are considered (5.5 vs. 10.5% BMS=OR 0.52). The two-year adjusted results confirm a significant advantage of SES in TVR (8.3 vs. 13.7% BMS=OR 0.65), a slight benefit for revascularizations (18.3 vs. 25.6% BMS=OR 0.76), without reducing mortality and other clinical events; these data refute the benefit on primary endpoint observed at 12 months (25.8 vs. 32.4% BMS=OR 0.84). After analyzing events recorded during the first and second year follow-up periods separately, the incidence of many of them favors SES in the first year, yet appear independent of the technique utilized in the second. RESTEM results confirming SES's capacity to reduce TVR without reduction of other clinical events, suggest that this advantage is limited to the first year after PCI, and show no evidence of excess of deaths, AMIs and late thrombosis following SES implantation described in recent meta-analyses.

In vivo coronary plaque histology in patients with stable and acute coronary syndromes: relationships with hyperlipidemic status and statin treatment.

OBJECTIVES: Aim of the study was to investigate whether maintained moderate statin treatment influence atheroma, macrophage content, neoangiogenesis and/or haemorrhage in coronary plaques from patients with non-fatal coronary syndromes. METHODS: A total of 48 patients underwent elective directional coronary atherectomy on "de novo" culprit lesions; 16 patients had non-treated hypercholesterolemia, 16 patients received maintained moderate statin treatment for hypercholesterolemia and 16 had no lipoprotein abnormalities. These three patients groups were matched for age and clinical diagnosis of stable angina (SA) or unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI). Atherectomy specimens were stained with antibodies against macrophages, endothelial cells and glycophorin A. Results of histology and immunohistochemistry were morphometrically analyzed by using computer-assisted image analysis. RESULTS: Atheroma and fibrous tissue, neoangiogenesis, macrophage and haemorrhage (i.e., glycophorin A) differed between the three groups (P<0.05). Statin-treated group showed significantly decreased atheroma (P=0.016), fibrous tissue (P=0.42), macrophage content (P=0.012), neoangiogenesis (P=0.00048) and haemorrhage (P=0.0092) as compared with the non-treated hyperlipidemic group. CONCLUSIONS: The present findings show that maintained moderate statin treatment may contribute to plaque stabilization in non-fatal coronary syndromes by decreasing intraplaque neoangiogenesis and haemorrhage, lipid burden and macrophage content, and, on the other hand, by increasing plaque collagenization.

Coronary rotational atherectomy in current practice: acute and mid-term results in high- and low-volume centers.

We conducted a prospective observational study to evaluate the indications, technique, in-hospital and 9-month results of consecutive patients treated with rotational atherectomy (RA) in 12 centers during 1 year, as well as their relationship with volume of RA activity. The study included 345 lesions in 289 patients treated (4.4% +/- 2.6% of procedures at the participating centers). The lesions were mostly calcified (63%) and type B2 or C (74%). Procedural success was obtained in 94% of patients, with a major adverse cardiac event (MACE) rate of 4.5%. At 9 months, MACE occurred in 17.3%. Multivariate analysis identified multivessel disease and slow flow as negative predictors of procedural success, whereas balloon pressure

Effective plaque removal with a new 8 French-compatible atherectomy catheter.

The purpose of this study was to evaluate the safety and efficacy of the new 8 Fr guide catheter-compatible Flexicut directional atherectomy device and to compare it with the conventional Atherocath GTO catheter. The 6 Fr Flexicut catheter has a larger cutting window and a titanium nitride-coated cutter to effect more tissue removal as well as treat mildly calcified lesions. A group of 143 lesions in 117 consecutive patients treated with the Flexicut catheter in four centers were compared with a control group of 277 lesions in 212 consecutive patients treated with the GTO device. Postatherectomy luminal diameters were larger (2.92 +/- 0.79 vs. 2.52 +/- 0.64 mm; P < 0.0001), with more luminal gain (relative gain: 0.58 +/- 0.24 vs. 0.48 +/- 0.25; P = 0.0007) using fewer directional coronary atherectomy (DCA) cuts (12 +/- 7 vs. 16 +/- 9; P = 0.0001) in the Flexicut group. A residual diameter stenosis < 20% immediately after DCA was obtained in 77% of the lesions in the Flexicut group vs. 45% in the GTO group (P < 0.0001). Histology in the former group revealed large calcium speckles in the retrieved specimens. In the Flexicut group, there was a lower incidence of access site complications and damage to the coronary ostium (2.5% vs. 7.5%; P = 0.08). The new Flexicut catheter is more effective than the conventional GTO catheter with a trend for reduced guiding catheter-related complications.