Impact of a micro-net mesh technology covering stent on coronary microvascular dysfunction in patients with high thrombus burden.

BACKGROUND: Highly thrombotic coronary lesions continue to be a serious and clinically significant problem that is not effectively and completely addressed by current technology. OBJECTIVES: We aimed to investigate whether a micro-net mesh (MNM) technology covering stent could preserve the index of microcirculatory resistance (IMR) after percutaneous coronary intervention (PCI) in patients with high thrombus burden. METHODS AND RESULTS: Fifty-two patients with non-ST elevation myocardial infarction or ST Elevation Myocardial Infarction and high thrombus burden (TIMI thrombus grade ≥ 3) were randomized into two groups, PCI with a MNM covering stent (MNM group, n = 25) and PCI with any commercially available stent (DES group, n = 27). As the primary endpoint, IMR was measured immediately after PCI using a pressure-temperature sensor-tipped coronary wire. The secondary endpoint was left ventricular ejection fraction (LVEF) at 6 months of follow-up. The IMR in the MNM group was significantly lower in comparison to the DES group (33.2 [21.3, 48.9] vs. 57.2 [39.9, 98.0], p = 0.005). No significant differences were observed in baseline LVEF (54.5 ± 10.2% vs. 53.1 ± 6.87%, p = .57), while LVEF was significantly improved at follow-up in the MNM group (61.1 ± 7.1% vs. 53.9 ± 6.35%, p = .0001). CONCLUSION: MNM technology significantly improved coronary microvascular dysfunction after PCI in patient with acute coronary syndrome and appears as a useful technological option for thrombus management.

The impact of atrio-biventricular pacing on hemodynamics and left ventricular dyssynchrony compared with atrio-right ventricular pacing alone in the postoperative period after cardiac surgery.

OBJECTIVES: The aims of this study were to test the hypotheses that in the postoperative period after coronary artery bypass graft surgery (1) atrio-right ventricular (RA-RV) pacing induces a decrease in cardiac output compared with RA pacing alone and (2) atrio-biventricular (RA-BiV) pacing improves CO compared with RA-RV pacing. DESIGN: A prospective observational study. SETTING: A single-center university hospital. PARTICIPANTS: Patients referred for coronary artery bypass graft surgery. INTERVENTIONS: Patients were studied during atrial, RA-RV, and RA-BiV pacing. Cardiac output (echocardiography) and left ventricular dyssynchrony were assessed at each step. MEASUREMENTS AND MAIN RESULTS: RA-RV pacing induced a significant decrease in cardiac output (4.3 +/- 1.0 to 3.7 +/- 0.8 L/min, p < 0.01) and a significant increase in left ventricular dyssynchrony (13 +/- 12 to 80 +/- 25 milliseconds, p < 0.01). Biventricular pacing induced a significant increase in cardiac output (3.7 +/- 0.8 to 4.5 +/- 1.0 L/min, p < 0.01) and a significant decrease in left ventricular dyssynchrony compared with right ventricular pacing (80 +/- 25 to 21 +/- 16 milliseconds, p < 0.05). CONCLUSIONS: RA-BiV pacing improves cardiac output compared with RA-RV pacing in the postoperative period after coronary artery bypass graft surgery. This improvement is related to an improvement in left ventricular synchronicity.

Ability of pleth variability index to detect hemodynamic changes induced by passive leg raising in spontaneously breathing volunteers.

INTRODUCTION: Pleth Variability Index (PVI) is a new algorithm that allows continuous and automatic estimation of respiratory variations in the pulse oximeter waveform amplitude. Our aim was to test its ability to detect changes in preload induced by passive leg raising (PLR) in spontaneously breathing volunteers. METHODS: We conducted a prospective observational study. Twenty-five spontaneously breathing volunteers were enrolled. PVI, heart rate and noninvasive arterial pressure were recorded. Cardiac output was assessed using transthoracic echocardiography. Volunteers were studied in three successive positions: baseline (semirecumbent position); after PLR of 45 degrees with the trunk lowered in the supine position; and back in the semirecubent position. RESULTS: We observed significant changes in cardiac output and PVI during changes in body position. In particular, PVI decreased significantly from baseline to PLR (from 21.5 +/- 8.0% to 18.3 +/- 9.4%; P < 0.05) and increased significantly from PLR to the semirecumbent position (from 18.3 +/- 9.4% to 25.4 +/- 10.6 %; P < 0.05). A threshold PVI value above 19% was a weak but significant predictor of response to PLR (sensitivity 82%, specificity 57%, area under the receiver operating characteristic curve 0.734 +/- 0.101). CONCLUSION: PVI can detect haemodynamic changes induced by PLR in spontaneously breathing volunteers. However, we found that PVI was a weak predictor of fluid responsiveness in this setting.

Primary angioplasty: Effect of deferred stenting on stent size.

BACKGROUND: Primary angioplasty with immediate stenting (IS) is the gold standard for ST-segment elevation myocardial infarction (STEMI). Deferred stenting (DS) has been proposed to limit periprocedural complications, and may influence stent size because of thrombus and spasm alleviation. AIM: We sought to study the effect of DS on stent size. METHODS: Over the study period, 258 patients underwent primary angioplasty for STEMI (DS, n=84; IS, n=174). An informative coronary angiogram run - i.e. allowing for proper lesion analysis - was selected and anonymized by an independent operator. Two experienced operators randomly analysed these runs, and proposed stent dimensions after having measured vessel diameter and lesion length by quantitative coronary analysis. The primary objective was the variation in stent size between the two coronary angiograms. RESULTS: The median delay between the two coronary angiograms was 2 days. Overall, the stent length was shorter (-1.64mm; P=0.030) and its diameter was larger (+0.13mm; P<0.001) during the second coronary angiogram, especially in the right coronary arteries. CONCLUSIONS: DS led to the implantation of a larger and shorter stent; this is probably because DS allows for more accurate assessment of the residual lesion after relief of spasm and thrombus, and may have clinical consequences in terms of stent thrombosis and restenosis.

Deferred vs immediate stenting in ST elevation myocardial infarction: Potential interest in selected patients.

BACKGROUND: Slow flow, no reflow and distal embolization often occur during primary angioplasty in ST segment elevation myocardial infarction (STEMI), compromising optimal myocardial reperfusion. AIMS: This study aimed at assessing the impact of deferred stenting (DS) on periprocedural events as compared to immediate stenting (IS). The second objective was to gather the reasons advocated by the physicians for deferring stenting. METHODS: All consecutive patients referred for primary angioplasty were included between September 2010 and November 2011. Physicians were free to choose the strategy between DS and IS but had to justify their choice. DS patients underwent a coronary angiogram control in a delay > 24h. RESULTS: Ninety-eight patients were included. Forty patients underwent DS and 58 IS. DS strategy involved thrombus management by thromboaspiration (33 patients 82.5%) and by the use of AntiGpIIbIIIa (23 patients 62.2%). This strategy could be achieved with a low complication rate. In particular, one patient had a reocclusion leading to a rapid reintervention and one had a distal embolization. In comparison, 11 periprocedural events occurred in the IS subgroup. In addition, among DS patients, 7 were treated medically because of a non-significant stenosis. The major criteria considered by the operator to prefer DS in the presence of a TIMI 3 flow concerned thrombotic load. CONCLUSION: This mono-centric experience confirmed the feasibility and the safety of DS. On top of reducing periprocedural events, it may allow for other treatment options in selected STEMI patients, e.g. surgery or medical treatment. The reasons leading physicians to choose DS were large thrombus burden on top of resolution of chest pain and normalization of the ECG. These criteria could help selecting situations in which DS may be of particular value as compared to IS.

Association of various blood pressure variables and vascular phenotypes with coronary, stroke and renal deaths: Potential implications for prevention.

The relationship between blood pressure (BP) and cardiovascular diseases has been extensively documented. However, the benefit of anti-hypertensive drugs differs according to the type of cardiovascular event. Aortic stiffness is tightly intertwined with BP and aorta cross-talk with small arteries. We endeavored to elucidate which BP component and type of vessel remodeling was predictive of the following outcomes: fatal myocardial infarction (MI), fatal stroke, renal -, coronary- or cerebrovascular-related deaths. Large vessel remodeling was estimated by an aortography-based aortic atherosclerosis score (ATS) while small vessel disease was documented by the presence of a hypertensive retinopathy. We included 1031 subjects referred for hypertension workup and assessed outcomes 30 years later. After adjustment for major risk factors, ATS and pulse pressure (PP) were predictive of coronary events while mean BP (MBP) and retinopathy were not. On the contrary, MBP was predictive of cerebrovascular and renal related deaths while ATS and PP were not. Retinopathy was only predictive of cerebrovascular related deaths. Lastly, the aortic atherosclerosis phenotype and increased PP identified patients prone to develop fatal MI whereas the retinopathy phenotype and increased MBP identified patients at higher risk of fatal stroke. These results illustrate the particular feature of the resistive coronary circulation comparatively to the brain and kidneys' low-resistance circulation. Our results advocate for a rational preventive strategy based on the identification of distinct clinical phenotypes. Accordingly, decreasing MBP levels could help preventing stroke in retinopathy phenotypes whereas targeting PP is possibly more efficient in preventing MI in atherosclerotic phenotypes.