P1296 Effects of contact-to-balloon time on variations of the left ventricle global and regional function during hospitalization of STEMI patients: an echocardiographic study

Background

Ischemic time duration is one of the most important determinants of infarct size in patients with ST-segment elevation myocardial infarction (STEMI). An early reperfusion with percutaneous coronary intervention (PCI) therapy reduces the adverse events and mortality. It also influences the wall motion abnormalities and left ventricular ejection fraction (LVEF), which can be easily detected by a standard transthoracic echocardiogram (TTE).

Purpose

Aim of our study was to assess the immediate effects of an early percutaneous revascularization in STEMI patients on variations of the left ventricle (LV) global and regional function.

Methods

The study population consists of 141 consecutive patients with STEMI undergoing PCI from January to June 2018. The population was divided into two groups basing on first medical contact-to-balloon time (C2B), respectively ≤90 minutes and >90 minutes. Cardiac biomarkers were obtained uniformly. A standard TTE was performed in all patients, at moment of in-hospital admission and at the time of discharge, recording the LV wall motion abnormalities and LVEF, using the wall motion score index (WMSI) and modified Simpson’s rule, respectively. Finally, we performed a sub-analysis in the group of patients who showed an improvement of the LVEF ≥10% at discharge.

Results

In both groups at baseline, patients suffered from a moderately reduced LVEF (41 ± 8.3% in ≤90 min group vs 40.97 ± 8.91% in >90 min group, p = ns). A WMSI >1 was recorded uniformly: 1.78 ± 0.39 in patients with C2B ≤90 min and 1.81 ± 0.40 in patients with C2B >90 min, without significant differences between the two groups. At the time of discharge, a significant improvement of LVEF (from 41 ± 8% to 44 ± 9%, p = 0.013) and WMSI (from 1.78 ± 0.39 to 1.64 ± 0.38, p = 0.036) exclusively emerged in the ≤90 min group. Furthermore, we identified 37 patients who experienced, at the time of discharge, an improvement of the LVEF ≥10% compared to baseline values. In these patients the C2B time resulted significantly shorter, when compared with patients with LVEF improvement <10%: 42 min (IQR 18.5-77.5) vs. 104 (IQR 48-176), p < 0.0001. Additionally, these patients had lower significant levels of cardiac biomarkers. A significant improvement in WMSI was also observed in the ≥10% group (1,69 ± 0,41 vs 1,49 ± 0,41, p= 0.039).

Conclusion

Our study shows the immediate effects of an early revascularization. In particular, the duration of C2B time influences the recovery of ventricular function, in terms of ejection fraction and parietal kinetics. A standard TTE is a low cost and easily available examination, which may provide immediate results without impacting significantly on health costs.

Evaluation of dentin root canal permeability after instrumentation and Er:YAG laser application

BACKGROUND AND OBJECTIVES

Smear layer removal with EDTA from root canal walls allows greater cleaning and disinfection of root canals. However, because Er:YAG laser acts on the removal of the smear layer, the objective of investigation was to analyze in vitro the effect of Er:YAG laser on dentin root canal wall permeability after endodontic instrumentation and irrigation with water or sodium hypochlorite and Er:YAG laser application.

STUDY DESIGN/MATERIALS AND METHODS

A total of 25 extracted human maxillary incisors were divided into five groups: Group I, instrumentation with deionized distilled water as the irrigating solution; Group II, instrumentation with 1% sodium hypochlorite as the irrigating solution; Group III, instrumentation with deionized distilled water as the irrigating solution and Er:YAG laser application; Group IV, instrumentation with 1% sodium hypochlorite solution as the irrigating solution and Er:YAG laser application; Group V, instrumentation only up to #20 file with deionized distilled water as the irrigating solution and Er:YAG laser irradiation. The laser parameters were 15 Hz, 140 mJ, total energy 42 J, 300 pulses (Kavo Key Laser). Copper sulfate (10%) was used to evaluate dentin permeability. The penetration of copper ions into the dentinal tubules was observed using 1% rubeanic acid, which reveals copper ions, forming a stained compound ranging in color from deep blue to black. Transverse sections (500-microm thick) were obtained with a diamond disk from the cervical, middle, and apical thirds.

RESULTS

The instrumentation of the root canal that used water as the irrigating solution followed by Er:YAG laser irradiation promoted the greatest increase in dentin permeability. The use of Er:YAG laser, 1% sodium hypochlorite + Er:YAG, and 1% sodium hypochlorite used alone showed an intermediate capacity of increasing dentin permeability. The use of water as the irrigating solution without Er:YAG laser promoted the least dentin permeability.

CONCLUSIONS

The use of water as the irrigating solution after instrumentation and Er:YAG laser irradiation was an effective procedure for increasing dentin permeability.

[Acute silicosis in jewelry casting]

An accelerated silicosis case made our Occupational Health Unit focus on a pathology thought dropping so far to die out. Furthermore this event occurred in a manufacturing (lost-wax process in jewelry casting) regarded as a low-risk exposure. Besides unsuitable procedures, the user had underestimated the specific risk of that raw material (talcum-like powder at 60-80% silica crystalline level), commonly called "gypsum", inappropriately labelled since not yet adequately classified by the hazardous substances list. The widespreading of this manufacture in our area (Vicenza district) and the recent inclusion of Silica Crystalline in the Class 1 made by IARC (Jan 1997) have urged this Unit to take action in industrial hygiene investigations, instructions to the workers, mandatory directions to dealers concerning the proper hazard labelling for products containing silica crystalline and circulation of information among other Occupational Health Units involved.

[Lead poisoning caused by stonework treatment in architectural restoration]

An unexpected lead exposure occurred among a team of masons employed in restoration work of the facade of an 18th century church in Vicenza, Italy. The unusual case of lead intoxication (PbB up to 71 micrograms/dL, PbU-EDTA 8636 micrograms/24 h after the first 1 g dose of Na2Ca EDTA) in a mason suffering from abdominal pain was reported to our unit by the local General Hospital. An investigation on the possible sources was therefore set up and the source was identified in the removal of an old paint made of white lead (basic lead carbonate) from the statues and decorative stonework of the church. An extension of the investigation confirmed that many sculptures and stonework from the same period, especially in religious buildings, were treated in the same way. The biological exposure indices of the subject's work fellows also confirmed an abnormal lead absorption. The occupational risks involved in various methods in restoration crafts are evaluated and preventive measures are suggested.