Absence of preinfarction angina is associated with a risk of no-reflow phenomenon after primary coronary angioplasty for a first anterior wall acute myocardial infarction

Coronary No-Reflow after Primary Percutaneous Coronary Intervention-Current Knowledge on Pathophysiology, Diagnosis, Clinical Impact and Therapy

Coronary no-reflow (CNR) is a frequent phenomenon that develops in patients with ST-segment elevation myocardial infarction (STEMI) following reperfusion therapy. CNR is highly dynamic, develops gradually (over hours) and persists for days to weeks after reperfusion. Microvascular obstruction (MVO) developing as a consequence of myocardial ischemia, distal embolization and reperfusion-related injury is the main pathophysiological mechanism of CNR. The frequency of CNR or MVO after primary PCI differs widely depending on the sensitivity of the tools used for diagnosis and timing of examination. Coronary angiography is readily available and most convenient to diagnose CNR but it is highly conservative and underestimates the true frequency of CNR. Cardiac magnetic resonance (CMR) imaging is the most sensitive method to diagnose MVO and CNR that provides information on the presence, localization and extent of MVO. CMR imaging detects intramyocardial hemorrhage and accurately estimates the infarct size. MVO and CNR markedly negate the benefits of reperfusion therapy and contribute to poor clinical outcomes including adverse remodeling of left ventricle, worsening or new congestive heart failure and reduced survival. Despite extensive research and the use of therapies that target almost all known pathophysiological mechanisms of CNR, no therapy has been found that prevents or reverses CNR and provides consistent clinical benefit in patients with STEMI undergoing reperfusion. Currently, the prevention or alleviation of MVO and CNR remain unmet goals in the therapy of STEMI that continue to be under intense research.

A score system to predict no-reflow in primary percutaneous coronary intervention: The PIANO Score

BACKGROUND

Angiographic no-reflow is associated with poor outcomes in patients with ST-segment elevation myocardial infarction (STEMI). We sought to develop and validate a score system to predict angiographic no-reflow in primary percutaneous coronary intervention (PCI).

METHODS

ST-segment elevation myocardial infarction patients undergoing primary PCI were consecutively enrolled and were randomly divided into the training and validation set. Angiographic no-reflow was defined as thrombolysis in myocardial infarction (TIMI) flow grade 0 to 2 after PCI. In the training set, independent predictors were identified by logistic regression analysis, and a score system (PredIction of Angiographic NO-reflow, the PIANO score) was constructed based on the β-coefficient of each variable. The established model was evaluated for discrimination and calibration.

RESULTS

Angiographic no-reflow occurred in 362 (17.8%) of 2036 patients. Age ≥70 years, absence of pre-infarction angina, total ischaemic time ≥4 h, left anterior descending as culprit artery, pre-PCI TIMI flow grade ≤1 and pre-PCI TIMI thrombus score ≥4 were independent predictors of angiographic no-reflow. The PIANO score ranged from 0 to 14 points, yielding a concordance index of 0.857 (95% confidence interval: 0.833 to 0.880), with good calibration. In the high-risk (≥8 points) group, the probability of angiographic no-reflow phenomenon was 38.7%, while it was only 4.8% in the low-risk (<8 points) group. The score system performed well in the validation set.

CONCLUSIONS

We establish and validate a score system based on six clinical variables to predict angiographic no-reflow in STEMI patients undergoing primary PCI, which may help choose the optimal individual treatment strategy.

Predictors of no- reflow during primary angioplasty for acute myocardial infarction, from Medical College Hospital, Trivandrum

Background

Primary angioplasty (PCI) for acute myocardial infarction is associated with no-reflow phenomenon, in about 5–25% of cases. Here we analysed the factors predicting no reflow .

Methods

This was a case control study of consecutive patients with acute myocardial infarction who underwent Primary PCI from August 2014 to February 2015.

Results

Of 181 patients who underwent primary PCI, 47 (25.9%) showed an angiographic no-reflow phenomenon. The mean age was 59.19 ± 10.25 years and females were 11%.

Univariate predictors of no reflow were age >60 years (OR = 6.146, 95%CI 2.937–12.86, P = 0<0.001), reperfusion time >6 h (OR = 21.94, 95%CI 9.402–51.2, P = < 0.001), low initial TIMI flow (≤1) (OR = 12.12, 95%CI 4.117–35.65, P < 0.001), low initial TMPG flow (≤1) (OR = 36.19, 95%CI 4.847–270.2, P < 0.001) a high thrombus burden (OR = 11.04,95%CI 5.124–23.8, P < 0.001), a long target lesion (OR = 8.54, 95%CI 3.794–19.23, P < 0.001), Killip Class III/IV(OR = 2.937,95%CI 1.112–7.756,P = 0.025) and overlap stenting(OR = 3.733,95%CI 1.186–11.75,P = 0.017).

Multiple stepwise logistic regression analysis predictors were: longer reperfusion time > 6 h (OR = 13.844, 95%CI 3.214–59.636, P = <0.001), age >60 years (OR = 8.886, 95%CI 2.145–36.80, P = 0.003), a long target lesion (OR = 8.637, 95%CI 1.975–37.768, P = 0.004), low initial TIMI flow (≤1) (OR = 20.861, 95%CI 1.739–250.290, P = 0.017).

Conclusions

It is important to minimize trauma to the vessel, avoid repetitive balloon dilatations use direct stenting and use the shortest stent if possible.

Time-dependent effect of preinfarction angina pectoris and intermittent claudication on mortality following myocardial infarction: A Danish nationwide cohort study

BACKGROUND

As proxies for local and remote ischemic preconditioning, we examined whether preinfarction angina pectoris and intermittent claudication influenced mortality following myocardial infarction.

METHODS

Using medical registries, we conducted a nationwide population-based cohort study of all first-time myocardial infarction patients in Denmark during 2004-2012 (n=70,458). We computed all-cause and coronary mortality rate ratios (MRRs). We categorized time between angina/claudication presentation and subsequent myocardial infarction as 0-14, 15-30, 31-90, and > 90 days. We adjusted for age, sex, coronary intervention, comorbidities, and medication use.

RESULTS

Among all myocardial infarction patients, 18.4% had prior angina and 3.8% had prior intermittent claudication. Compared to patients without prior angina, the adjusted 30-day coronary MRR was 0.85 (95% confidence interval (CI): 0.80-0.92) for stable and 0.68 (95% CI: 0.58-0.79) for unstable angina patients. The mortality reduction increased when angina presented close to myocardial infarction and was higher for unstable than for stable angina. Thus, the 30-day coronary MRR was 0.72 (95% CI: 0.51-1.02) for stable angina and 0.35 (95% CI: 0.17-0.73) for unstable angina presenting within 14 days before MI. The results were robust for all-cause mortality and in numerous subgroups, including women, diabetics, patients treated with PCI, and patients treated with and without cardioprotective drugs. Preinfarction intermittent claudication was associated with higher short- and long-term mortality compared to patients without intermittent claudication.

CONCLUSIONS

Preinfarction angina reduced 30-day mortality, particularly when unstable angina closely preceded MI. Preinfarction intermittent claudication was associated with increased short- and long-term mortality.

Prodromal angina is associated with myocardial salvage in acute ST-segment elevation myocardial infarction

AIMS

Previous studies have shown that prodromal angina (PA) occurs frequently in acute myocardial infarction (MI) patients. However, the potential benefits of PA on ischaemic myocardial damage remain unknown.

METHODS AND RESULTS

One-hundred and fifty-four patients with acute ST-segment elevation MI successfully treated with primary percutaneous coronary intervention (PPCI) were prospectively evaluated for new-onset PA in the week preceding infarction and other factors known to influence myocardial salvage. Cardiovascular magnetic resonance was performed 8 ± 3 days after MI for the assessment of area-at-risk (AAR), MI size, myocardial haemorrhage (MH), microvascular obstruction (MO), and myocardial salvage index (MSI). Patients with PA (n = 60) compared with those without PA (n = 94) showed similar AAR but significantly smaller MI size leading to larger MSI (0.53 ± 0.27 vs. 0.32 ± 0.26, P < 0.001). Additionally, patients with PA had lower incidence of MH (18 vs. 33%) and MO (22 vs. 46%) than non-PA patients (both P < 0.05). At univariate analysis, higher MSI was associated with new-onset PA, lower myocardial oxygen consumption before PPCI, shorter time-to-PPCI, and higher post-procedural TIMI flow-grade. Neither collateral circulation nor medications administered before PPCI were associated to MSI. After correction for other covariates by multivariate analysis, new-onset PA remained significantly associated with MSI (β-value: 0.352, P < 0.001).

CONCLUSION

In acute MI patients, new-onset PA is associated with higher MSI independent of others factors known to influence jeopardized myocardium, as well as with less microvascular damage.

Role of ischemic preconditioning and inflammatory response in the development of malignant ventricular arrhythmias after reperfused ST-elevation myocardial infarction

BACKGROUND

Sustained ventricular tachycardia and ventricular fibrillation (VT/VF) are major complications of ST-elevation myocardial infarction (STEMI), even in the era of reperfusion therapy. We sought to clarify the determinants of VT/VF after reperfused STEMI.

METHODS AND RESULTS

Consecutive STEMI patients treated with primary percutaneous coronary intervention (n=457) were divided into 2 groups by the presence or absence of VT/VF during hospitalization. Serum C-reactive protein (CRP) level and peripheral white blood cell (WBC) count were serially measured. VT/VF was observed in 54 patients (12%). Prior infarction was more common and preinfarction angina was less in patients with VT/VF than those without. Peak CRP level (P < .0001), WBC count on admission (P=.008), and maximum WBC count (P=.0014) were higher in patients with VT/VF than those without. VT/VF, especially VT/VF later than 48 hours after onset, was associated with greater left ventricular (LV) dimension during convalescence. Kaplan-Meier curves and log-rank test revealed VT/VF to be a significant determinant of long-term major adverse cardiac events. Multivariate analysis revealed that prior infarction, absence of preinfarction angina, and peak CRP >or=10mg/dL were independent determinants of VT/VF.

CONCLUSIONS

Lack of ischemic preconditioning, enhanced inflammatory response, and subsequent LV dysfunction are related to the development of VT/VF after STEMI.

Determinants and prognostic implications of reperfusion injury during primary percutaneous coronary intervention in Chinese patients with acute myocardial infarction

BACKGROUND

The poor clinical outcome in acute myocardial infarction (AMI) patients undergoing primary percutaneous coronary intervention (PCI) has been attributed to myocardial ischemia-reperfusion injury (MIRI).

OBJECTIVE

This study aimed to identify the predictive factors of MIRI during PCI in Chinese AMI patients with or without ST-segment elevation.

METHODS

Clinical and angiographic data of 228 patients in whom the infarct-related artery (IRA) was successfully recanalized by primary PCI were retrospectively analyzed. Multiple logistic regressions were used.

RESULTS

Compared with non-MIRI group (n=109), patients with MIRI (n=119) were characterized by more inferior infarct location, shorter ischemic duration, more frequently right coronary artery as IRA, more lesion vessels, more often thrombolysis in myocardial infarction (TIMI) 0 flow in IRA prior to PCI, less preinfarction angina, and more renal insufficiency. Ischemic time<or=6 hours (p=0.014), inferior infarct location (p=0.006), and initial antegrade flow in IRA<or=TIMI grade 1 (p=0.028) were independent risk factors for MIRI. Other risk factors included multivessel lesions (p=0.063) and renal insufficiency (p=0.067). Only preinfarction angina was a protective factor (p=0.005).

CONCLUSIONS

The factors promoting MIRI during primary PCI includes short ischemic time from AMI onset to IRA recanalization, inferior infarct location, low IRA antegrade flow prior to PCI, multivessel lesions, and renal insufficiency, whereas preinfarction angina is a protective factor attenuating MIRI.

Management of 'no-reflow' complicating reperfusion therapy

No-reflow phenomenon, defined as inadequate myocardial perfusion of the adequately dilated target vessel without evidence of angiographic mechanical obstruction. It is a multifactorial, well-recognised, secondary phenomenon following reperfusion therapy such as thrombolysis or percutaneous coronary interventions (PCI). The pathophysiological mechanisms leading to the no-reflow state are incompletely understood. Embolization of the atheromatous material to the distal vasculature and intense arteriole vasospasm caused by microembolization of platelet-rich thrombi that release vasoactive agents resulting in microvascular obstructions are likely mechanisms. Current prophylaxis and management strategies are derived from limited clinical data. Intracoronary verapamil, adenosine and nitroprusside have been most frequently studied and administered for angiographic no-reflow during PCI for acute myocardial infarction or saphenous vein graft (SVG) lesions and have been shown to improve epicardial flow and microvascular perfusion. The use of distal embolic protection devices in SVG interventions also provide microvascular protection and improve clinical outcomes. However, by far the most important measures are prevention and anticipation during PCI as once no-reflow established, complete reversal of the situation may not be possible.

Aging Adversely Affects Postinfarction Inflammatory Response and Early Left Ventricular Remodeling after Reperfused Acute Anterior Myocardial Infarction

BACKGROUND AND AIMS

We have demonstrated that an increased peak serum C-reactive protein (CRP) level after acute myocardial infarction (AMI) was a major predictor of left ventricular (LV) remodeling. We sought to clarify the effect of aging on the postinfarction inflammatory response and LV remodeling.

METHODS

We studied 102 patients who underwent primary angioplasty for a first anterior Q-wave AMI. Serum CRP levels, plasma neurohormones and interleukin-6 (IL-6) levels, and LV volume by left ventriculography were serially measured. Patients were divided into two groups according to their age (>or=70 years, n=33; <70 years, n=69).

RESULTS

There was no difference in use of cardiovascular drugs and coronary angiographic findings. Older patients had a greater increase in LV end-diastolic volume during 2 weeks after AMI (p=0.0007) and a higher peak CRP level (12.4+/-7.3 vs. 5.5+/-4.2 mg/dl, p<0.0001), although peak CK level was comparable between the two groups. Plasma atrial natriuretic peptide, brain natriuretic peptide and IL-6 levels were higher in older patients at 2 weeks and 6 months after AMI.

CONCLUSIONS

Augmented and prolonged activation of the inflammatory system after AMI was observed in older patients, in association with exaggerated LV remodeling. Aging may adversely affect LV remodeling through modification of the inflammatory response after AMI.

Ischemic preconditioning and preinfarction angina in the clinical arena

In animals, brief episodes of ischemia before a total coronary occlusion protect the heart and result in a smaller myocardial infarct size. In humans, episodes of angina before acute myocardial infarction might also confer a preconditioning or protective effect; numerous studies show that preinfarction angina is associated with smaller infarcts. Preinfarction angina is also associated with reductions in ventricular dysfunction, arrhythmias and incidence of no-reflow phenomena, and, in some cases, improved survival. The protective effect of preconditioning in humans is characterized by marked individual variations and seems to be attenuated in women, people with diabetes and the elderly. Exercise seems to be an important way to induce preconditioning in humans and preserves it in the elderly.

Early Administration of Intracoronary Verapamil Improves Myocardial Perfusion During Percutaneous Coronary Interventions for Acute Myocardial Infarction

BACKGROUND

Intracoronary calcium-channel blockers administered in the event of no reflow during percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) have been shown to improve myocardial perfusion.

STUDY OBJECTIVE

To evaluate the effects of the administration of intracoronary verapamil before the occurrence of no reflow during direct PCI.

DESIGN AND SETTING

Single-center, nonrandomized, prospective study with a retrospective control group.

PATIENTS AND METHODS

From September 2001 to December 2003, 50 consecutive patients with AMI were prospectively enrolled for intracoronary verapamil treatment. Intracoronary verapamil was administered immediately prior to balloon inflation and at short intervals during the procedure thereafter. Retrospectively, 50 consecutive AMI patients who had undergone direct PCI and had not received intracoronary calcium-channel blockers were enrolled as control subjects. Patients with cardiogenic shock or platelet glycoprotein IIb/IIIa inhibitor were excluded. Thrombolysis in Myocardial Infarction (TIMI) flow grade, corrected TIMI frame count (CTFC), and TIMI myocardial perfusion grade (TMPG) were assessed prior to and following PCI by two independent cardiologists blinded to the procedures.

RESULTS

The two groups had similar baseline and post-procedural angiographic characteristics, although the patients who been administered verapamil received more stent implantations than the control subjects (84% vs 60%, p = 0.008). Post-procedural TIMI flow < 3 (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.12 to 1.30; p = 0.18) and TMPG (OR, 1.24; 95% CI, 0.46 to 3.34; p = 0.68) were not associated with the implantation of the stents. There were no significant difference in post-PCI TIMI flow (p = 0.68) and CTFC (p = 0.36) between patients treated with verapamil and the control subjects. Post-PCI TMPG was significantly better in patients treated with intracoronary verapamil (p = 0.003). Forty-two percent of the patients treated with verapamil were found to have TMPG-3, while only 14% of the control subjects were found to have the same degree of TMPG (p = 0.004). Treatment with intracoronary verapamil (OR, 0.26; 95% CI, 0.12 to 0.58; p = 0.001) and pre-PCI TIMI flow (OR, 0.54; 95% CI, 0.35 to 0.84; p = 0.006) were found by multiple logistic regression to be independent predictors of TMPG.

CONCLUSIONS

Early administration of intracoronary verapamil during direct PCI improves post-procedural myocardial perfusion, as evaluated by TMPG.

Is the Beneficial Effect of Preinfarction Angina Related to an Immune Response?

Immune-mediated mechanisms are thought to play a key role in the development of coronary artery disease and its thrombotic complications. Preinfarction angina has been suggested to improve left ventricular function and short-term outcomes. The purpose of the present study was to investigate the relation between the immune response and in-hospital clinical course in preinfarction angina. We prospectively evaluated 93 patients. Forty-three patients exhibited preinfarction angina within 24 hours before the onset of acute myocardial infarction (AMI) (preinfarction angina group) and 50 patients were free from preinfarction angina (sudden onset group). The incidence of complications (heart failure, recurrent angina, arrhythmia and coronary interventions) and in-hospital mortality were assessed in the two study groups. We detected some immune markers, including white blood cells, C-reactive protein, immunoglobulins, and complement. White blood cells and CRP were significantly lower in the preinfarction angina group than in the sudden onset group (P < 0.001, P < 0.005, respectively). Conversely, IgE and C(4) were significantly higher in the preinfarction angina group than in the sudden onset group (P < 0.001, P < 0.001, respectively). The incidences of heart failure and severe arrhythmias were lower in the preinfarction group than in the sudden onset group (P < 0.005, P < 0.05 respectively). The beneficial effect of preinfarction angina may be associated with an immune-inflammatory response modified by a brief ischemic episode.

Treatment of no-reflow phenomenon with verapamil after primary stent deployment during myocardial infarction

No-reflow phenomenon is the absence of myocardial perfusion despite adequate dilatation of the infarct related coronary artery during percutaneous coronary intervention. It predicts severe left ventricular dysfunction and poor prognosis in acute myocardial infarction (AMI). The present case is a 54 year old Turkish female who presented with chest pain that had started 2.5 hours earlier. The clinical and laboratory findings were consistent with AMI and the coronary angiogram performed for primary angioplasty revealed a 95% thrombotic occlusion with a TIMI grade I flow in the left anterior descending (LAD) coronary artery. A TIMI grade III flow was achieved with direct stent deployment. However, after the placement of a second stent for severe ostial stenosis more proximally and adjacent to the first one, the antegrade flow became TIMI grade O. As the intracoronary medications did not improve the flow, a mechanical occlusion was considered and a third stent was deployed covering the first two stents. A control angiogram revealed the persistence of TIMI grade O flow. A severe and persistent vasospasm was considered at this point and accordingly, intracoronary verapamil was administered in high concentrations by an infusion catheter to the distal LAD which was followed by the immediate achievement of TIMI grade III flow. Intracoronary administration of high dose verapamil can be performed to prevent vasospasm in resistant no-reflow cases with no evidence of mechanic occlusion.

Effect of preinfarction angina pectoris on ST-segment resolution after primary coronary angioplasty for acute myocardial infarction

The presence of preinfarction angina has been shown to exert a favorable effect on left ventricular function after acute myocardial infarction (AMI). Whether or not preinfarction angina is beneficial for myocardial tissue reperfusion, however, remains to be determined. We sought to evaluate the influence of preinfarction angina on resolution of ST-segment elevation, which could be affected by microcirculatory damage after recanalization therapy. We studied 96 patients with a first AMI in whom Thrombolysis In Myocardial Infarction (TIMI)-3 flow in the infarct-related artery was established by primary angioplasty. Percent reduction in the sum of ST elevation from baseline to 1 hour after angioplasty (percent delta summation operator ST) was examined. Poor ST resolution, defined as percent delta summation operator ST <50%, was observed in 25 patients, who had a worse clinical outcome, larger infarct size, and poorer left ventricular function. On multivariate analysis, the absence of preinfarction angina, as well as anterior wall infarction, were major independent predictors of poor ST resolution, whereas age, sex, coronary risk factors, ischemic time, Killip class on admission, multivessel disease, initial TIMI flow grade, and extent of collaterals were not significant. Patients with preinfarction angina had a greater degree of ST-segment resolution than those without angina (71 +/- 21% vs 49 +/- 43%, p = 0.02). Additional ST elevation after reperfusion was noted exclusively in patients without preinfarction angina (p = 0.02). Preinfarction angina is associated with a greater degree of ST-segment resolution in patients with TIMI-3 flow after primary angioplasty, suggesting a protective effect of preinfarction angina against microcirculatory damage after reperfusion.

Failed reperfusion after thrombolytic therapy: recognition and management

BACKGROUND

Failed reperfusion after thrombolysis occurs in as many as 30% of patients with acute myocardial infarction (MI). Furthermore, some patients have incomplete tissue perfusion despite reperfusion of the infarct-related artery. Close assessment of the efficacy of thrombolytic administration in people with evolving acute MI is necessary, particularly with regard to myocardial perfusion status, because some patients may benefit from incremental pharmacologic or invasive reperfusion strategies.

PURPOSE AND METHOD

This article reviews a number of strategies to assess infarct-related artery patency and myocardial tissue perfusion. These include coronary angiography, continuous ST-segment monitoring, serial electrocardiography, obtaining serial serum biochemical markers of myocardial necrosis, monitoring for reperfusion arrhythmias, and assessment of changes in chest pain intensity.

CONCLUSION

The early detection of failed reperfusion is critical if incremental strategies to enhance myocardial salvage are to be considered. Continuous ST-segment monitoring is a relatively inexpensive, reliable, and accurate tool for assessing real-time myocardial perfusion.