Effects of reflowing temperature and time on alloy layer of tinplate and its electrochemical behavior in 3.5%NaCl solution

Effects of reflowing temperature and time on the alloy layer of tinplate and its electrochemical behavior in 3.5%NaCl solution were investigated by electrochemical measurements and surface characterization.It is found that the amount of alloy layer increases with the increase of reflowing temperature and time.Then the corrosion potential of detinned tinplate shifts positively and the corrosion rate decreases.After being coupled with tin,the detinned tinplate acts as cathode and tin acts as anode initially.However,after being exposed for some time,the potential shifts of both detinned tinplate and tin reverse the polarity of the coupling system.The galvanic current density decreases with the increase of reflowing temperature and time.

FORMATION AND CHANGE OF AuSn_4 COMPOUNDS AT INTERFACE BETWEEN PBGA SOLDER BALL AND Au/Ni/Cu METALLIZATION DURING LASER AND INFRA-RED REFLOW SOLDERING

Interactions between 63Sn37Pb solder and PBGA metallization (Au/Ni/Cu) duringlaser and infrared reflow soldering were studied. During laser reflow soldering process,a thin layer of AuSn_4 was observed at the interface of the solder bumps, its morphologywas strongly dependent on the laser reflow power and heating time. The solder bumpsformed by the first laser reflow was reflowed again to form the solder joints. TheAuSn_4 compounds formed in the first laser reflow process dissolved into the bulk solderafter the secondary infrared reflow process. The needle-like AuSn_4 changed into rod-like, and distributed inside the solder near the solder/pad interface.

Effects of preinfarction angina on no-reflow phenomenon after percutaneous coronary intervention in patients with acute myocardial infarction

Objective To evaluate effects of preinfarction angina(PA) on no reflow phenomenon after percutaneous coronary intervention(PCI) in patients with acute myocardial infarction(AMI).Methods one hundred patients with first AMI were divided into no reflow group( n =15)and reflow group( n =85). All patients undervent PCI within 12h after onset of AMI.No reflow phenomenon,defined as TIMI grade 2 flow or less without apparent residual stenosis .Myocardial enzyme was continuously measured;Left ventricular function was assessed by radionuclideimaging; The incidence of ventricular aneurysm and in hospital mortality was observed. Results (1)Patients with no reflow had a significantly lower incidence of PA( 20% vs 61% , P <0.01 ), a higher incidence of anterior infarction (67%vs35%, P <0.05 ), and had significantly higher peak creatine MB fraction than those with reflow(403±132vs277±151, P <0.01 ).(2) Patients with no reflow had significantly larger myocardial infarction area (MIA) ( 27.6 ±9.1% vs 20.9 ±9.4% , P <0.01 ), significantly higer left ventricular ejection fraction (46±8% vs 53±9%, P <0.01 ),and had a higher incidence of ventricular aneurysm and mortality than those with reflow (20%vs4%,p<0.05;20% vs 2%, P <0.05 ). (3)Multivariate Logistic analysis showed that the absence of preinfarction angina was a major independent determinant of no reflow( OR = 6.12 , P =0.01 ).Conclusions The absence of preinfarction angina is a high dangerous factor of no reflow phenomenon; No reflow phenomenon is associated with a high incidence of heart failure and mortality.

Protective effect of Danhong injection in patients with acute myocardial infarction at a high risk of no-reflow during primary percutaneous coronary intervention

Objective To observe the effect of Danhong injection(DI)in patients with acute ST-segment elevation myocardial infarction(STEMI)at a high risk of no-reflow(NR)during primary percutaneous coronary intervention(PCI).Methods Patients were placed in a DI group and control group.The DI group was given DI and the control group was given physiologic saline.The administration lasted 4 to 6 days in both groups after PCI.Cardiac magnetic resonance(CMR)was carried out during the perioperative period(7±2 days).The primary endpoint of the study was myocardial infarct size(IS)imaged on delayed-enhancement CMR.The secondary endpoint was major adverse cardiac events observed 6 months after PCI.Results In total,160 high-risk NR patients were enrolled,and 110 patients completed the CMR examination.According to postoperative CMR,the Myocardial Salvage Index and left ventricular ejection fraction were higher in the DI group(0.57±0.13 vs.0.48±0.17,P<0.01;49.3%±6.9%vs.46.2%±7.7%,P=0.03,respectively),whereas the IS was lower(19.7%±5.6%vs.22.2%±6.5%,P=0.04),compared with that in the control group.These differences were observed to be significant.After 6 months,the prevalence of major adverse cardiac events in the DI group decreased compared with that in the control group,but the differences were not observed to be significant(P>0.05).Conclusion The application of DI can reduce the myocardial infarct size in STEMI patients at a high risk of NR during primary PCI.

Removal of the main inflorescence to induce reflowering of loquat

Loquat(Eriobotrya japonica Lindl.)is an evergreen fruit tree species of the Rosaceae,and its unique flowering time greatly hinders its production.To explore the artificial regulation of loquat flowering time,we removed the main inflorescence(by cutting it)to induce reflowering.For different loquat tree cultivars with different stages,the inflorescence was removed by cutting the main floral axis at two alternative positions:the upper or the lower position beneath the inflorescence,and it was found that the proportion of reflowering resulting from removing the upper position of the main floral axis of yellow-flesh loquat cultivars during the full-bloom stage was the highest.In addition,compared with those of the normal-growing panicles,the number of flower buds and branch axes of the reflowering panicles decreased significantly after cutting.Importantly,these newly produced inflorescences flowered 2–4 months later than normal-growing inflorescences did,effectively prolonging both the flowering and fruiting time.In addition,qRT-PCR results showed that EjFT1,EjFT2,EjAP1–1 and EjAP1–2 were highly expressed in the floral axis.These findings highlighted a new method for extending the production cycle of loquat and provided a reference for the flowering regulation of loquat and other economically important fruit tree species.

Evolution of AuSnx intermetallic compounds in laser reflowed micro-solder joints

To investigate the effect of Au thickness on evolution of AuSnx IMCs, pads with 0. 1, 0. 5 and 4. 0 μm thickness of Au surface finish were utilized. Laser reflowed solder joints were aged in 125℃ isothermal ovens. Results indicated that little IMC formed at the interface of solder and pad with 0. 1 μm thickness of Au. Even in condition of 744 hours aging, thickness of lMCs did not increase obviously. As for the joints with 0. 5 μm thickness of Au, most of AuSn4 IMCs stayed at the inteornce and were in needle-like or dendritic morphology. With the increase of aging time, AuSn4 IMCs beeame flat and changed to a continuous layer. In the joints with 4. 0 μm thickness of Au on pads, AuSn, AuSn2, AuSn4 IMCs and Au2Sn phase formed at the interface. As aging time was increased, more Sn rich IMCs formed at the interface, and evolved to AuSn4 IMCs in condition of long time aging. Thickness of AuSn4 IMCs reached about 30μm.

Value of Platelet to Lymphocytes Ratio in Predicting Angiographic Reflow after Primary Percutaneous Coronary Intervention in STEMI Patient

Background: Acute myocardial infarction is a leading cause of death worldwide nowadays and treatment of choice is primary percutaneous coronary intervention (PCI). No reflow is a complication that increases mortality and morbidity post intervention and one of its predictors is platelet lymphocyte ratio. Aim of Study: To assess relation between admission platelet to lymphocyte ratio (PLR) and angiographic reflow after primary PCI in acute ST elevation myocardial infarction (STEMI). Patients and Methods: This is a prospective study that was conducted from May 2017 to May 2018 at Cardiology Department, Menoufia University Hospital. Sixty patients presented with ST-elevation myocardial infarction who were eligible for primary PCI were enrolled in the study. According to TIMI flow post intervention, patients were arranged into 2 groups: Group 1 (Normal Reflow) included thirty patients with post intervention TIMI flow III and Group 2 (NO Reflow) included thirty patients with post intervention TIMI flow (0, I, II). Comparison between both groups was done regarding platelet lymphocyte ratio (PLR). Result: PLR was significantly higher in patients with coronary no reflow than in patients with normal reflow with a P-value of , timing interval between onset of chest pain to time of intervention and thrombus grading was significantly higher in patients with no reflow than in patients with normal reflow. Conclusion: Pre-intervention PLR is an independent predictor of slow flow/no reflow following PPCI in patient with acute STEMI.

Study on detinning process of a reflow conductor roll

Adhering tin is the main reason of a reflow conductor roll which works in an electroplating tin line （ETL）. A det- inning agent whose main composition is NaOH and KOH and assistant composition is Na2PbO2 or K2PbO2 and NaNO3 or NaNO2 has excellent detinning effects when the temperature of detinning solution is 40-80℃ and the temperature of the reflow conductor roll reaches 40-70℃. After the adhering tin layer of the reflow conductor roll is removed, the roughness of the reflow conductor roll can resume to 4.0 μm, its service life increases by 80%, and the repairing cost decreases by 90%.

Failure Mechanism of Reflow Conductor Roll of Electroplating Tinning Line

The surface roughness of reflow conductor roll was checked on membrane sample. The surface morphology of conductor roll was observed by microscope, and the composition of adhered layer on conductor roll surface was analyzed by X-ray spectroscope. The results show that tin adhesion is the main reason for failure of conductor roll, and the failure of conductor roll is accelerated by wear. The measures to decrease tin adhesion and improve wear resistance were put forward.

Failure Modes of Lead Free Solder Bumps Formed by Induction Spontaneous Heating Reflow

The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated through the shear test after aging at 120℃ for 0, 1, 4, 9 and 16 d. Different typical shear failure behaviors have been found in the loading curves （shear force vs displacement）. From the results of interracial morphology analysis of the fracture surfaces and cross-sections, two main typical failure modes have been identified. The probabilities of the failure modes occurrence are inconsistent when the joints were aged for different times. The evolution of the brittle NiaSn4 and Cu-Ni-Au-Sn layers and the grains coarsening of the solder bulk are the basic reasons for the change of shear failure modes.

Characteristics of Laser Reflow Bumping of Sn3.5Ag and Sn3.5Ag0.5Cu Lead-Free Solder Balls

ead-free Sn3.5Ag and Sn3.5Ag0.5Cu solder balls were reflowed by laser to form solder bumps. Shear test was performed on the solder bumps, and SEM/EDX （scanning electron microscopy/energy dispersive X-ray spectrometer） was used to analyze the formation of intermetallic compounds （IMCs） at interface region. A finite element modeling on the temperature gradient and distribution at the interface of solder bump during laser reflow process was conducted to elucidate the mechanism of the IMCs growth direction. The results show that the parameters window for laser reflow bumping of Sn3.5Ag0.5Cu was wider than that of Sn3.5Ag. The shear strength of Sn3.5Ag0.5Cu solder bump was comparable to that of Sn3.5Ag solder bump, and was not affected obviously by laser power and irradiation time when appropriate parameters were used. Both laser power and heating time had a significant effect on the formation of IMCs. A continuous AuSn4 intermetallic compound layer and some needle-like AuSn4 were observed at the interface of solder and Au/Ni/Cu metallization layer when the laser power is small. The formation of needle-like AuSn4 was due to temperature gradient at the interface, and the direction of temperature gradient was the preferred growth direction of AuSn4. With increasing the laser power and heating time, the needle-like AuSn4 IMCs dissolved into the bulk solder, and precipitated out once again during solidification along the grain boundary of the solder bump.

Study on laser and hot air reflow soldering of PBGA solder ball

Laser and hot air reflow soldering of PBGA solder ball was investigated. Experimental results showed that surface quality and shear strength of solder bump reflowed by laser was superior than the solder bump by hot air, and the microstructure within the solder bump reflowed by laser was much finer. Analysis on interfacial reaction showed that eutectic solder reacted with Au/Ni/Cu pad shortly after the solder was melted. Interface of solder bump reflowed by laser consists of a continuous AuSn 4 layer and remnant Au element. Needle like AuSn 4 grew sidewise from interface, and then spread out to the entire interface region. A thin layer of Ni 3Sn 4 intermetallic compound was found at the interface of solder bump reflowed by hot air, and AuSn 4 particles distributed within the whole solder bump randomly. The combination effect of the continuous AuSn 4 layer and finer eutectic microstructure contributes to the higher shear strength of solder bump reflowed by laser.

Predictive Factors of No Reflow during Primary Angioplasty

Introduction: No reflow during primary angioplasty is associated with a poor prognosis despite the reopening of the culprit coronary. The aim of our work was to determine the predictive factors of no reflow. Methodology: Single-center retrospective analytical study from June 2000 to December 2016 that included patients presenting with STEMI took care of by primary angioplasty. No reflow was defined according to angiographic criteria: a TIMI flow Results: The prevalence of no reflow was 24%. In univariate analysis mean age, diabetes,hypertension, tachycardia, hypotension, killip stage 4 left ventricular failure, hyperglycemia > 11, renal failure, left ventricular dysfunction, tritruncal status, common trunk involvement, initial TIMI flow at 0, significant thrombotic load, delay to angioplasty > 6 hours, and predilation were all correlated with no reflow with a p 75 years [OR = 6.02, 95% CI 1.4 - 27, p = 0.014], tachycardia [OR = 4.3, 95% CI 1.6 - 7.4, p = 0.037], delay to angioplasty > 6 hours [OR = 1.3, 95% CI 1.1 - 2.1, p = 0.003] and high thrombotic load [OR = 1.5, 95% CI 1.3 - 3.2, p = 0.02] were independent predictors of no reflow. Conclusion: No reflow is associated with a poor short-term prognosis. Its care requires knowledge of predictive factors, prevention and treatment.

Related factors of coronary no-reflow phenomenon and progress of traditional Chinese medicine treatment

Coronary no-reflow phenomenon belongs to a type of coronary microcirculation disturbance,and its main pathogenic factors are vascular endothelial cell injury,microembolism and inflammatory reaction,which are corresponding to the pathogenesis of choroid injury,blood stasis and heat toxin in traditional Chinese medicine,such as NO,ET-1,chemokine,IL and other cytokines.The degree of improvement of patients'symptoms and laboratory examination data provide a basis for traditional Chinese medicine compound prescription,monomer and traditional Chinese medicine characteristic therapy for the treatment of no-reflow phenomena(NRP).Combined with related factors,the author summarizes the research progress of traditional Chinese medicine treatment of NRP in recent years,in order to provide clinical reference.

Effect of intracoronary sodium nitroprusside and tirofiban injection on myocardial injury in patients with no reflow in PCI

Objective: To study the effect of intracoronary sodium nitroprusside and tirofiban injection on myocardial injury in patients with no reflow in PCI. Methods: Patients with acute coronary syndrome who underwent PCI and had no reflow in Gong'an County People's Hospital in Hubei Province between August 2014 and July 2017 were selected as the research subjects and randomly divided into two groups, combined group accepted intracoronary sodium nitroprusside and tirofiban injection during PCI, and control group accepted intracoronary tirofiban injection during PCI. The serum levels of myocardial injury indexes, oxidative stress indexes and inflammatory mediators of the two groups were measured before treatment and 1 d after treatment. Results: 1 d after treatment, serum CK-MB, H-FABP, sFas, cMyBP-C, MPO, MDA, Caspase-3, MCP-1, IL-1β, IL-18, MMP2 and MMP9 levels of both groups were significantly lower than those before treatment whereas SOD and NQO-1 levels were higher than those before treatment, and serum CK-MB, H-FABP, sFas, cMyBP-C, MPO, MDA, Caspase-3, MCP-1, IL-1β, IL-18, MMP2 and MMP9 levels of combined group were significantly lower than those of control group whereas SOD and NQO-1 levels were higher than those control group. Conclusion: Intracoronary sodium nitroprusside and tirofiban injection can reduce the myocardial injury in patients with no reflow in PCI.

Effect of intracoronary administration of anisodamine on slow reflow phenomenon following primary percutaneous coronary intervention in patients with acute myocardial infarction

Background Many basic and clinical studies have proved that anisodamine can produce significant effect on relieving microvascular spasm, improving and dredging the coronary microcirculation. It may be beneficial to the improvement of slow-reflow phenomenon （SRP） following percutaneous coronary intervention （PCI） for acute myocardial infarction （AMI）. So we investigated the effect of intracoronary administration of anisodamine on SRP of infarct related artery （IRA） following primary PCI in patients with ST segment elevated acute myocardial infarction （STEAMI）. Methods Twenty-one patients with SRP from a total of 148 STEAMI patients accepted primary PCI were enrolled into this study from September 2004 to December 2005. When SRP happened, nitroglycerin （200 μg） was ＂bolus＂ injected firstly into IRA to exclude the spasm of epicardial artery and identify SRP as well as a baseline and self-control agent following PCI. Ten minutes later, 1000 μg of anisodamine was injected into IRA with SRP at 200 μg/s, while the coronary angiography （CAG） was taken before and at 1st, 3rd and 10th minute after administration of nitroglycerin or anisodamine, respectively. The corrected TIMI frame count （cTFC）, TIMI myocardial perfusion grade （TMPG） and the diameter of IRA were calculated and analyzed by Gibson＇s TIMI frame count method using quantitative computer angiography （QCA） system to evaluate the influence of anisodamine on coronary flow and vessel lumen. In the meantime the invasive hemodynamic parameters of intracoronary and systemic artery （systolic, diastolic and mean pressure） and electrocardiogram （ECG） were measured and monitored. The changes of ventricular performance parameters and the adverse reaction were evaluated and followed-up at 1 month post-PCI. Results No significant changes in cTFCs and TMPGs were found at 1st, 3rd and 10th minute after intracoronary administration of nitroglycerin as compared with the baseline control （P〉0.05）. cTFCs were decreased by 58.3%, 56.2% and 54.6%, respectively （P〈0.001）, and TMPGs were increased from 1.13±0.21 grade to 2.03±0.32, 2.65±0.45 and 2.51±0.57 grades （P〈0.05） at 1st, 3rd and 10th minute after intracoronary administration of anisodamine as compared with those after intracoronary administration of nitroglycerine, respectively. The average coronary blood flow of TIMI grade was improved from 1.76±0.43 to 2.71±0.46 （P〈0.05） while the diameter of middle segment in re-patented coronary artery was slightly increased from （3.20±0.40） mm to （3.40±0.50） mm at the 3rd minute after intracoronary administration of anisodamine （P〉0.05） as compared with those of nitroglycerine control. The systolic, diastolic and mean pressures of intracoronary artery after intracoronary administration of anisodamine increased from 115 to 123, 75 to 84, 88 to 95 mmHg （P〈0.05）, respectively, along with the rise of heart rate from 68 to 84 beats per minute （P〈0.05）. There were no significant changes in intervals of PR, QT and QRS （P〉0.05） and no any severe fast arrhythmia after intracoronary administration of anisodamine. The ventricular performance parameters were significantly improved and no major adverse cardiovascular events （MACE） were found during follow-up at 1 month post-PCI. Conclusions Intracoronary administration of 1000 μg anisodamine is effictive in reversing SRP following PCI in STEAMI patients, especially it is suitable for SRP patients with bradycardia or hypotension.

Effect of Chinese Medicine on No or Slow Reflow after Percutaneous Coronary Intervention in Myocardial Infarction Patients: A Systematic Review and Meta-Analysis

Objective:To systematic review the effect of Chinese medicine(CM)on no or slow reflow after percutaneous coronary intervention(PCI)in myocardial infarction(MI)patients.Methods:The Pub Med,EMBASE databases,Cochrane Central Register of Controlled Trials(CENTRAL),Web of Science,China National Knowledge Infrastructure(CNKI),Chinese BioMedical Literature Database(CBM),Wanfang Knowledge Service Platform(Wanfang Database)and Chinese Scientific Journal Database(VIP)were searched up to December 2017.Randomized controlled trials(RCTs)which evaluated the effect of CM therapies on no or slow reflow after PCI in MI patients were included.The primary outcome was the effect of reperfusion.Secondary outcomes were left ventricular ejection fraction,incidence of major adverse cardiovascular events and adverse effect.Results:Ten RCTs covering 814 patients were included.Two studies revealed that the incidence of no or slow reflow was less in Shenmai Injection(参麦注射液)group than in the control group measured by thrombolysis in myocardial infarction(TIMI)2(risk ratio=0.55,95%confidence interval 0.38 to 0.81,P=0.003,I^2=37%).Two studies indicated that Salvianolate Injection showed no additional benefit on no or slow reflow measured by corrected TIMI frame count compared with the conventional treatment(mean difference–4.24,95% confidence interval–13.03 to 4.54,P=0.34,I^2=86%).In addition,Tongxinluo Capsules(通心络胶囊),Danhong Injection(丹红注射液)and Xuesaitong Injection(血塞通注射液)may have the potential to reduce no or slow reflow measured during or after PCI in individual studies.Conclusions:Current evidence from RCTs are not sufficient to evaluate the effect of CM adjuvant therapies on no or slow reflow after PCI for MI patients.The included studies are limited by small sample size and unclear baseline conditions.Further rigorously designed researches and verification studies with sufficient number of patients are warranted.

No-reflow protection and long-term efficacy for acute myocardial infarction with Tongxinluo： a randomized double-blind placebo- controlled multicenter clinical trial （ENLEAT Trial）

Background No-reflow after emergency percutaneous coronary intervention （PCI） for acute ST segment elevation myocardial infarction （STEMI） is related to the severe prognosis. The aim of this study was to evaluate the efficacy of Tongxinluo, a traditional Chinese medicine, on no-reflow and the infarction area after emergency PCI for STEMI.Methods A total of 219 patients （female 31, 14%） undergoing emergency PCI for STEMI from nine clinical centers were consecutively enrolled in this randomized, double-blind, placebo-controlled, multicenter clinical trial from January 2007 to May 2009. All patients were randomly divided into Tongxinluo group （n=108） and control group （n=111）, given Tongxinluo or placebo in loading dose 2.08 g respectively before emergency PCI with asprin 300 mg and clopidogrel 300 mg together, then 1.04 g three times daily for six months after PCI. The ST segment elevation was recorded by electrocardiogram at hospitalization and 1, 2, 6, 12, 24 hours after coronary balloon dilation to evaluate the myocardial no-flow; myocardial perfusion scores of 17 segments were evaluated on day 7 and day 180 after STEMI with static single-photon emission computed tomography （SPECT） to determine the infarct area.Results There was no statistical significance in sex, age, past history, chest pain, onset-to-reperfusion time, Killip classification, TIMI flow grade just before and after PCI, either in the medication treatment during the follow up such as statin, β-blocker, angiotensin converting enzyme inhibitor （ACEI） or angiotensin receptor blocker （ARB） between two groups. There was significant ST segment restoration in Tongxinluo group compared to the control group at 6 hours （（-0.22±0.18） mV vs. （-0.18±0.16） mV, P=0.0394）, 12 hours （（-0.24 ± 0.18） mV vs. （-0.18±0.15） mV, P=0.0158） and 24 hours （（-0.27±0.16） mV vs. （-0.20±0.16） mV, P=0.0021） reperfusion; and the incidence of myocardial no-reflow was also reduced significantly at 24-hour reperfusion （34.3% vs. 54.1%, P=0.0031）. The myocardial perfusion scores of 17 segments evaluated by static SPECT was improved significantly on day 7 and day 180 after STEMI in Tongxinluo group compared to the control group （0.61±0.40 vs. 0.76±0.42, P=0.0109 and 0.51 ±0.42 vs. 0.66±0.43, P=0.0115, respectively）.There was no significant difference in severe adverse events between two groups.Conclusion Tongxinluo as a kind of traditional Chinese medicine could reduce myocardial no-reflow and infarction area significantly after emergency PCl for STEMI with conventional medicine therapy.

Effect of pre-procedural statin therapy on myocardial no-reflow following percutaneous coronary intervention： a meta analysis

Background Successful revascularization of coronary artery disease, especially ST-elevation myocardial infarction （STEMI）, does not always mean optimal myocardial reperfusion in a portion of patients because of no-reflow phenomenon. We hypothesized that statins might attenuate the incidence of myocardial no-reflow when used before percutaneous coronary intervention （PCI）. The purpose of this study was to summarize the evidence of pre-procedural statin therapy to reduce myocardial no-reflow after PCI. Methods We searched the MEDLINE, Cochrane, and clinicaltrials.gov databases from inception to October 2012 for clinical trials that examined statin therapy before PCI. We required that studies initiated statins before PCI and reported myocardial no-reflow. A DerSimonian-Laird model was used to construct random-effects summary risk ratios. Results In all, 7 studies with 3086 patients met our selection criteria. The use of pre-procedural statins significantly reduced post-procedural no-reflow by 4.2% in all PCI patients （risk ratio （RR） 0.56, 95% confidence interval （CI） 0.35 to 0.90, P=0.016）, and attenuated by 5.0% in non-STEMI patients （RR 0.41, 95% CI 0.18 to 0.94, P=0.035）. This benefit was mainly observed in the early or acute intensive statin therapy populations （RR 0.43, 95% CI 0.26 to 0.71, P=0.001）. Conclusions Acute intensive statin therapy before PCI significantly reduces the hazard of post-procedural no-reflow phenomenon. The routine use of statins before PCI should be considered.