Release of matrix metalloproteinases following alcohol septal ablation in hypertrophic obstructive cardiomyopathy

Metalloproteinases and Hypertrophic Cardiomyopathy: A Systematic Review

Hypertrophic cardiomyopathy (HCM) is a genetic condition determined by an altered collagen turnover of the extracellular matrix. Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are abnormally released in patients with HCM. The purpose of this systematic review was to thoroughly summarize and discuss the existing knowledge of MMPs profile in patients with HCM. All studies meeting the inclusion criteria (detailed data regarding MMPs in patients with HCM) were selected, after screening the literature from July 1975 to November 2022. Sixteen trials that enrolled a total of 892 participants were included. MMPs-particularly MMP2-levels were found higher in HCM patients compared to healthy subjects. MMPs were used as biomarkers after surgical and percutaneous treatments. Understanding the molecular processes that control the cardiac ECM's collagen turnover allows for a non-invasive evaluation of HCM patients through the monitoring of MMPs and TIMPs.

Characteristics of myocardial postsystolic shortening in patients with symptomatic hypertrophic obstructive cardiomyopathy before and half a year after alcohol septal ablation assessed by speckle tracking echocardiography

Objectives

Postsystolic shortening (PSS) has been proposed as a marker of myocardial dysfunction. Percutaneous transluminal septal myocardial ablation (PTSMA) is an alternative therapy for patients with hypertrophic obstructive cardiomyopathy (HOCM) that results in sustained improvements in atrial structure and function. We investigated the effects of PTSMA on PSS in HOCM patients using speckle tracking imaging.

Methods

Conventional echocardiographic and PSS parameters were obtained in 18 healthy controls and 30 HOCM patients before and half a year after PTSMA.

Results

Compared with the healthy controls, the number of segments having PSS and the average value of PSS were significantly increased in the HOCM patients. At 6 months after PTSMA, both the number of segments having PSS (10.5±2.8 vs. 13.2±2.6; P<0.001) and the average value of PSS (−1.24±0.57 vs. −1.55±0.56; P = 0.009) were significantly reduced. Moreover, the reductions in the average value of PSS correlated well with the reductions in the E-to-Ea ratio (r = 0.705, P<0.001).

Conclusions

Both the number of segments having PSS and the average value of PSS were significantly increased in the HOCM patients. PTSMA has a favourable effect on PSS, which may partly account for the persistent improvement in LV diastolic function in HOCM patients after PTSMA.

Translating Koch's postulates to identify matrix metalloproteinase roles in postmyocardial infarction remodeling: cardiac metalloproteinase actions (CarMA) postulates

The first matrix metalloproteinase (MMP) was described in 1962; and since the 1990s, cardiovascular research has focused on understanding how MMPs regulate many aspects of cardiovascular pathology from atherosclerosis formation to myocardial infarction and stroke. Although much information has been gleaned by these past reports, to a large degree MMP cardiovascular biology remains observational, with few studies homing in on cause and effect relationships. Koch's postulates were first developed in the 19th century as a way to establish microorganism function and were modified in the 20th century to include methods to establish molecular causality. In this review, we outline the concept for establishing a similar approach to determine causality in terms of MMP functions. We use left ventricular remodeling postmyocardial infarction as an example, but this approach will have broad applicability across both the cardiovascular and the MMP fields.

Oral fluids that detect cardiovascular disease biomarkers

OBJECTIVE

The aim of this study was to determine the utility of oral fluids for assessment of coronary and cardiovascular (CV) health.

STUDY DESIGN

Twenty-nine patients with preexisting CV disease underwent an invasive cardiac procedure (alcohol septal ablation or percutaneous coronary intervention) and provided unstimulated whole saliva (UWS), sublingual swabs (LS), gingival swabs (GS) and serum at 0, 8, 16, 24, and 48 hours. Concentrations of 13 relevant biomarkers were determined and correlated with levels in serum and the oral fluids.

RESULTS

Concentrations of the majority of biomarkers were higher in UWS than in LS and GS. Coronary and CV disease biomarkers in UWS correlated better with serum than with LS and GS based on group status and measures of time effect. Seven biomarkers demonstrated time effect changes consistent with serum biomarkers, including C-reactive protein and troponin I.

CONCLUSIONS

Changes in serum biomarker profiles are reflected in oral fluids suggesting that oral fluid biomarkers could aid in the assessment of cardiac ischemia/necrosis.

Salivary biomarkers associated with myocardial necrosis: results from an alcohol septal ablation model

OBJECTIVE

To determine if salivary biomarkers demonstrate utility for identifying aspects of myocardial necrosis.

METHODS

Twenty-one patients undergoing alcohol septal ablation (ASA) for treatment of hypertrophic cardiomyopathy provided serum and unstimulated whole saliva at baseline and incremental time points post-ASA. Samples were analyzed for seven biomarkers related to myocardial damage, inflammation, and tissue remodeling using immunosorbent assays. Levels were compared with baseline and levels observed in 97 healthy controls.

RESULTS

Biomarkers of myocardial damage and inflammation (ie, troponin I, creatine kinase-MB, myoglobin, C-reactive protein) rose in serum 2- to 812-fold after ASA (P < .01). Significant elevations of 2.0- to 3.5-fold were observed with C-reactive protein and troponin I in saliva (P < .02). Significant correlations between levels in serum and saliva were observed for C-reactive protein, matrix metalloproteinase-9, and myeloperoxidase (P < .001).

CONCLUSIONS

Select salivary biomarkers reflect changes that occur during, and subsequent to, myocardial necrosis caused by ASA.

The design of inhibitors for medicinally relevant metalloproteins

A number of metalloproteins are important medicinal targets for conditions ranging from pathogenic infections to cancer. Many but not all of these metalloproteins contain a zinc(II) ion in the protein active site. Small-molecule inhibitors of these metalloproteins are designed to bind directly to the active site metal ions. In this review several metalloproteins of interest are discussed, including matrix metalloproteinases (MMPs), histone deacetylases (HDACs), anthrax lethal factor (LF), and others. Different strategies that have been employed to design effective inhibitors against these proteins are described, with an effort to highlight the strengths and drawbacks of each approach. An emphasis is placed on examining the bioinorganic chemistry of these metal active sites and how a better understanding of the coordination chemistry in these systems may lead to improved inhibitors. It is hoped that this review will help inspire medicinal, biological, and inorganic chemists to tackle this important problem by considering all aspects of metalloprotein inhibitor design.

Myocardial ischemia and reperfusion injury in rats: lysosomal hydrolases and matrix metalloproteinases mediated cellular damage

The aim of this study was to evaluate the time course events of cellular damage during myocardial ischemia and reperfusion injury in rats and to find out a correlation between the structural alterations with respect to the biochemical changes. Cardiac biomarkers and lysosomal enzymes viz. cathepsin D, acid phosphatase and beta-glucuronidase and matrix metalloproteinases (MMPs) were evaluated at different time points, in response to ischemia-reperfusion induced oxidative stress in an isolated rat heart model perfused in Langendorff mode. Microscopically, changes in myocardial architecture, myofibrillar degradation, and collagen (COL) integrity were studied using hematoxylin-eosin, Masson's trichrome and toluidine blue staining techniques. A three-fold increase in the level of myoglobin was observed after 30 min of ischemia followed by 120 min of reperfusion as compared to 15 min ischemia, 120 min reperfusion. Similarly, a significant increase (P<0.05) in the levels of lipid peroxides and superoxide anion coupled with a decrease in enzymatic and nonenzymatic antioxidant levels were observed. A concomitant increase in the activity of cathepsin D (24.07+/-0.95) and a higher expression of MMPs after 120 min of reperfusion following 30 min ischemia were shown to correlate with the myocardial damage as shown by histopathology, suggesting that free radical induced activation of cathepsin D and MMPs could mediate early damage during myocardial ischemia and reperfusion.

Myocardial Matrix Remodeling and the Matrix Metalloproteinases: Influence on Cardiac Form and Function

It is now becoming apparent that dynamic changes occur within the interstitium that directly contribute to adverse myocardial remodeling following myocardial infarction (MI), with hypertensive heart disease and with intrinsic myocardial disease such as cardiomyopathy. Furthermore, a family of matrix proteases, the matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs), has been recognized to play an important role in matrix remodeling in these cardiac disease states. The purpose of this review is fivefold: 1) to examine and redefine the myocardial matrix as a critical and dynamic entity with respect to the remodeling process encountered with MI, hypertension, or cardiomyopathic disease; 2) present the remarkable progress that has been made with respect to MMP/TIMP biology and how it relates to myocardial matrix remodeling; 3) to evaluate critical translational/clinical studies that have provided a cause-effect relationship between alterations in MMP/TIMP regulation and myocardial matrix remodeling; 4) to provide a critical review and analysis of current diagnostic, prognostic, and pharmacological approaches that utilized our basic understanding of MMP/TIMPs in the context of cardiac disease; and 5) most importantly, to dispel the historical belief that the myocardial matrix is a passive structure and supplant this belief that the regulation of matrix protease pathways such as the MMPs and TIMPs will likely yield a new avenue of diagnostic and therapeutic strategies for myocardial remodeling and the progression to heart failure.

Effects of age on plasma matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs)

BACKGROUND

The mechanisms causing age-dependent changes in left ventricular (LV) structure and function are not completely understood. Matrix metalloproteinase (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) constitute one important proteolytic pathway affecting LV remodeling. However, whether these determinants of extracellular matrix (ECM) composition change as a function of age has not been examined in an aging population free of clinically significant cardiovascular disease.

METHODS AND RESULTS

Subjects (n = 77, age 20-90 years) with no evidence of cardiovascular disease underwent echocardiography and measurement of plasma MMP-2, 7, 8, and 9 and TIMP-1, 2, and 4 (enzyme-linked immunosorbent assay). As subject age increased, volume/mass ratio decreased and mitral E/A ratio decreased. As subject age increased, MMP-2 increased (from 1188 +/- 99 ng/mL to 1507 +/- 76 ng/mL), MMP-7 increased (from 1.2 +/- 0.1 ng/mL to 3.1 +/- 0.6 ng/mL), MMP-9 decreased (from 29 +/- 7 ng/mL to 8 +/- 2 ng/mL), and TIMP-1, 2, and 4 increased (from 728 +/- 46 ng/mL to 1093 +/- 73 ng/mL, from 34 +/- 5 ng/mL to 53 +/- 6 ng/mL, and from 1.26 +/- 0.22 ng/mL to 2.34 +/- 0.30 ng/mL, respectively) (all P < .05). There were significant correlations between decreased LV volume/mass and E/A ratio and increased MMP-7 and TIMP-1 and 4.

CONCLUSIONS

MMPs and TIMPs changed as a function of age in the absence of clinically significant cardiovascular disease. These age-dependent alterations in MMP and TIMP profiles favor ECM accumulation and were associated with concentric remodeling and decreased LV diastolic function. Because of these age-dependent changes in this proteolytic system, the superimposition of disease processes such as myocardial infarction or hypertensive heart disease in the older subject may result in different myocardial ECM remodeling than that seen in a younger subject.

Imaging of matrix metalloproteinase activation and left ventricular remodeling

Although left ventricular (LV) remodeling may be adaptive in early phases of cardiac injury, continued remodeling is a pathologic process that is associated with poor prognosis and diminished cardiac function. Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes involved in the degradation of myocardial extracellular proteins and have been implicated in adverse cardiac remodeling. There is a growing body of literature that supports the role of specific MMPs in cardiac remodeling in both animal models and clinical studies. Conventional imaging of physiologic indices, such as perfusion and function, have been used to monitor LV remodeling. Recently, the potential advantage of targeted imaging of MMPs has been demonstrated, particularly if this is linked with physiologic imaging.

Percutaneous septal ablation with absorbable gelatin sponge in hypertrophic obstructive cardiomyopathy

The treatment of the hypertrophic obstructive cardiomyopathy (HOCM) by percutaneous transluminal septal myocardial ablation (PTSMA) with ethanol injection has greatly improved in the last years. This report describes the case of a patient with symptomatic drug-refractory HOCM who underwent an unsuccessful attempt to thrombose the septal artery by PTSMA with alcohol. It has therefore been decided to use small absorbant gelatin sponge (AGS) particles, obtaining immediate thrombotic occlusion of the artery and excellent hemodynamic results with immediate and permanent disappearance of the gradient. The patient progressed satisfactorily and displayed lower than average creatine kinase levels in comparison to the rest of our PTMSA patients. After 2 years of follow-up he still remains asymptomatic and without any gradient. These results suggest that PTSMA with AGS could be a valuable alternative treatment of HOCM.

Specific temporal profile of matrix metalloproteinase release occurs in patients after myocardial infarction: relation to left ventricular remodeling

BACKGROUND

Changes in matrix metalloproteinase (MMP) and tissue inhibitors of MMPs (TIMPs) contribute to left ventricular (LV) remodeling after myocardial infarction (MI). We tested the hypothesis that a specific plasma MMP/TIMP profile would emerge after MI and be associated with the degree of LV dilation.

METHODS AND RESULTS

LV end-diastolic volume and MMP/TIMP plasma profiles were determined in 53 age-matched control subjects and 32 post-MI patients from day 1 through 180 after MI. LV end-diastolic volume increased by > 38% at day 90 after MI (P < 0.05). MMP-9 increased by > 150% from control at day 1 after MI (P < 0.05) and remained elevated. MMP-8 rose to > 120% at day 3 after MI (P < 0.05) and fell to control values by day 5. TIMP-1 increased by > 60% from control at day 1 after MI (P < 0.05), whereas TIMP-2 increased only at later time points. Cardiac-specific TIMP-4 fell by 40% at day 5 after MI and remained reduced. A persistent or elevated MMP-9 at day 5 was accompanied by a 3-fold end-diastolic volume increase at day 28 (P < 0.05).

CONCLUSIONS

A specific temporal pattern of MMP/TIMPs occurred in post-MI patients that included an early and robust rise in MMP-9 and MMP-8 and a uniform fall in TIMP-4. These findings suggest that a specific MMP/TIMP plasma profile occurs after MI and holds both prognostic and diagnostic significance.

Chronic Matrix Metalloproteinase Inhibition Following Myocardial Infarction in Mice: Differential Effects on Short and Long-Term Survival

Left ventricular (LV) remodeling occurs after myocardial infarction (MI), and the matrix metalloproteinases (MMPs) contribute to adverse LV remodeling after MI. Short-term pharmacological MMP inhibition (MMPi; days to weeks) in animal models of MI have demonstrated a reduction in adverse LV remodeling. However, the long-term effects (months) of MMPi on survival and LV remodeling after MI have not been examined. MI was induced in adult mice (n = 131) and, at 3 days post-MI, assigned to MMPi [MI-MMPi: (s)-2-(4-bromo-biphenyl-4-sulfonylamino)-3-methyl-butyric acid (PD200126), 7.5 mg/day/p.o., n = 64] or untreated (MI-only, n = 67). Unoperated mice (n = 16) served as controls. The median survival in the MI-only group was 5 days, whereas median survival was significantly greater in the MI-MMPi group at 38 days (p < 0.05). However, with prolonged MMPi (>120 days), a significant divergence in the survival curves occurred in which significantly greater mortality was observed with prolonged MMPi (p < 0.05). LV echocardiography at 6 months revealed LV dilation in the MI-only and MI-MMPi groups (154 +/- 14 and 219 +/- 24 microl) compared with control (67 +/- 4 microl, p < 0.05), with a greater degree of dilation in the MI-MMPi group (p < 0.05). MMPi conferred a beneficial effect on survival early post-MI, but prolonged MMPi (>3 months) was associated with higher mortality and adverse LV remodeling. These unique results suggest that an optimal temporal window exists with respect to pharmacological interruption of MMP activity in the post-MI period.

Matrix modulation and heart failure: new concepts question old beliefs

PURPOSE OF REVIEW

Myocardial remodeling is a complex process involving several molecular and cellular factors. Extracellular matrix has been implicated in the remodeling process. Historically, the myocardial extracellular matrix was thought to serve solely as a means to align cells and provide structure to the tissue. Although this is one of its important functions, evidence suggests that the extracellular matrix plays a complex and divergent role in influencing cell behavior. This paper characterizes some of the notable studies on this dynamic entity and on adverse myocardial remodeling that have been published over the past year, which further question the belief that the extracellular matrix is a static structure.

RECENT FINDINGS

Progress has been made in understanding how the extracellular matrix is operative in the three major conditions (myocardial infarction, left ventricular hypertrophy due to overload, and dilated cardiomyopathy) that involve myocardial remodeling. Several studies have examined plasma profiles of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases following myocardial infarction and during left ventricular hypertrophy as surrogate markers of remodeling/remodeled myocardium. It has been demonstrated that bioactive signaling molecules and growth factors, proteases, and structural proteins influence cell-matrix interactions in the context of left ventricular hypertrophy. Finally, studies that either removed or added tissue inhibitor of metalloproteinases species in the myocardium demonstrated the importance of this regulatory protein in the remodeling process.

SUMMARY

Understanding the cellular and molecular triggers that in turn give rise to changes in the extracellular matrix could provide opportunities to modify the remodeling process.

Disruptions and detours in the myocardial matrix highway and heart failure

Myocardial remodeling invariably occurs in congestive heart failure (CHF) and is a response to a prolonged cardiovascular stress, which is characterized by a cascade of compensatory structural events. Remodeling of the myocardial interstitium occurs in CHF and likely contributes to the progression of the remodeling process. The myocardial matrix can be considered a biological highway in which a large amount of signaling proteins and structural proteins are being moved within the interstitium, entering and exiting the interstitial space, and docking to cellular components. The rates at which these events occur can accelerate and decelerate depending on the particular cardiac disease state and thereby can alter the course of myocardial remodeling. Once considered merely a scaffolding to align cells, the matrix plays a complex and divergent role in influencing cell behavior. For example, the matrix has a functional role in cell migration, proliferation, adhesion, and cell-to-cell signaling. In light of this, the myocardial matrix should not be regarded as merely a static structure, but rather, as a complex system of dynamic interactions between matrix molecules, signaling proteins, and transmembrane proteins. Specific strategies that are targeted at modifying activity along this matrix highway will likely alter the course of myocardial remodeling and heart failure.

Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy

HOCM is a rare disorder of myocardium that may result in asymmetrical left ventricular septal hypertrophy and dynamic outflow obstruction. This may result in hemodynamic sequel that leads to deterioration of functional class in the majority of patients. Alcohol septal ablation may provide symptomatic relief in the majority of patients who fail medical therapy or who experience significantly high outflow gradients.

Plasma monitoring of the myocardial specific tissue inhibitor of metalloproteinase-4 after alcohol septal ablation in hypertrophic obstructive cardiomyopathy

BACKGROUND

The overall goal of this study was to develop an assay procedure for measuring the relative abundance of tissue inhibitor of metalloproteinase (TIMP)-4 in plasma, and then use this approach to determine dynamic changes of TIMP-4 levels in hypertrophic obstructive cardiomyopathic (HOCM) patients after an acute myocardial infarction (MI). Matrix metalloproteinases (MMPs) contribute to tissue remodeling and are regulated by the endogenous TIMPs. TIMP-4 is observed to be expressed in higher abundance in the myocardium when compared with other types of tissues. Recent clinical studies have measured changes in TIMP-4 levels; however, these studies have been limited to measuring this protein from myocardial tissue samples. To date, no studies have monitored TIMP-4 levels in plasma samples.

METHODS AND RESULTS

Plasma TIMP-4 levels were examined (by semiquantitative immunoblotting) in normal (n=18) and HOCM (n=16) patients after alcohol-induced MI. Serial measurements of plasma TIMP-4 levels were examined up to 60 hours after alcohol-induced MI in patients with HOCM. Unglycosylated plasma TIMP-4 levels increased 250% in the HOCM patients when compared with normal controls. Total plasma TIMP-4 levels decreased by 20% at 30 hours after alcohol-induced MI.

CONCLUSIONS

The unique results demonstrated that an induction of a controlled MI, specifically through alcohol ablation, caused a reduction in plasma TIMP-4 levels in HOCM patients after alcohol-induced MI that would facilitate myocardial remodeling in the early post-MI setting.