Detection of early impairment of coronary flow reserve in patients with systemic sclerosis

Relationship between peripheral and coronary function using laser Doppler imaging and transthoracic echocardiography

Vascular dysfunction in the coronary and peripheral circulations is an early prognostic marker of future cardiovascular events. Measurements of coronary and peripheral vascular function in resistance vessels can be made, but rely on invasive procedures, which make them unsuitable for routine application. An assessment of the direct correlation between vascular responses in skin and coronary vessels has not been made previously. In 27 normal healthy subjects (18-55 years of age), we examined the relationship between peripheral and coronary vascular function. Cutaneous perfusion was measured using the non-invasive technique of laser Doppler imaging during iontophoresis of acetylcholine and sodium nitroprusside, and cutaneous vascular conductance was calculated (laser Doppler perfusion/mean arterial pressure). Coronary flow reserve was measured using transthoracic echocardiography during intravenous adenosine infusion. Mean diastolic velocities were measured at baseline and peak hyperaemic conditions from the Doppler signal recordings. CVR (coronary velocity reserve) was defined as the ratio of hyperaemic to basal mean diastolic velocities. There were significant positive correlations between CVR and cutaneous vascular conductance for acetylcholine (r=0.399, P=0.039) and sodium nitroprusside (r=0.446, P=0.020). These results support the idea that peripheral measurements of skin blood flow are representative of generalized microvascular function including that of the coronary circulation in normal healthy subjects.

Pattern and distribution of myocardial fibrosis in systemic sclerosis: a delayed enhanced magnetic resonance imaging study

OBJECTIVE

To assess the prevalence and pattern of myocardial fibrosis as detected by delayed enhanced magnetic resonance imaging (DE-MRI) in patients with systemic sclerosis (SSc), and to evaluate a possible association between myocardial fibrosis and cardiac arrhythmias.

METHODS

Forty-one patients with SSc underwent 24-hour Holter monitoring, Doppler echocardiography, and DE-MRI following gadolinium administration.

RESULTS

Technically acceptable DE-MRIs were obtained in 36 patients with SSc. Enhancement on DE-MRI, consistent with myocardial fibrosis, was observed in 24 of these patients (66%), and it was invariably midwall with a linear pattern, mostly involving basal and midcavity segments of the left ventricle. The volume of enhancement (total volume percentage index [TVPI]) did not differ between patients with diffuse SSc and those with limited SSc (mean +/- SD 1.46 +/- 1.73% versus 1.44 +/- 1.77%; P = 0.98). Patients with a long duration (> or = 15 years) of Raynaud's phenomenon had a greater number of enhancing segments (mean +/- SD 6.55 +/- 4.93 versus 2.96 +/- 3.46; P = 0.017) and a greater TVPI (mean +/- SD 2.44 +/- 1.97% versus 1.02 +/- 1.43%; P = 0.02) than those with a duration of Raynaud's phenomenon <15 years. Nineteen patients with SSc (53%) had abnormal Holter study results. Compared with patients with normal Holter study results, those with abnormal results had a greater number of enhancing segments (mean +/- SD 5.4 +/- 4.8 versus 2.5 +/- 2.9; P < 0.05) and a greater TVPI (mean +/- SD 2.1 +/- 1.9% versus 0.8 +/- 1.2%; P < 0.05).

CONCLUSION

DE-MRI can identify myocardial fibrosis in a significant percentage of patients with SSc and may be a useful noninvasive tool for determining cardiac involvement.

Primary myocardial involvement in systemic sclerosis

Systemic sclerosis (SSc) is a connective tissue disease characterized by diffuse vascular lesions and fibrosis. Primary myocardial involvement is common in SSc and, when clinically evident, appears as a poor prognostic factor. An increasing body of evidence suggests that myocardial involvement is due, at least in part, to microcirculation impairment with abnormal vasoreactivity, with or without associated structural abnormalities of the small coronary arteries or arterioles. Using conventional methods, myocardial perfusion impairment, systolic and diastolic left ventricular dysfunction and right ventricular dysfunction have been reported in SSc. Recently, tissue Doppler echocardiography and magnetic resonance imaging have confirmed these results. Vasodilators, such as calcium channel blockers and angiotensin converting enzyme inhibitors, improve both myocardial perfusion and function abnormalities.

Preclinical impairment of coronary flow reserve in patients with rheumatoid arthritis

Cardiovascular involvement in rheumatoid arthritis (RA) is common, although the true prevalence of cardiac abnormalities is difficult to measure, as much disease remains clinically silent. The pathogenesis of cardiac lesions in RA is related to the primary disorder of microcirculation with diffuse arteriolar and capillary lesions. Previous studies demonstrated that coronary flow reserve (CFR) is impaired in patients with connective tissue diseases (CTD). This review focuses on transthoracic Doppler echocardiography as a noninvasive method used to assess CFR in RA patients. CFR is early reduced in RA patients without clinical evidence of heart disease as a result of impaired microcirculation. CFR seems a useful technique able to follow-up and to assess effects of new drugs on RA patients.

Associations between left ventricular myocardial involvement and endothelial dysfunction in systemic sclerosis: noninvasive assessment in asymptomatic patients

OBJECTIVES

Systemic sclerosis (SSc) is a multisystem disorder characterized by widespread vascular lesions and fibrosis of skin and distinct internal organs. Cardiac involvement is a common finding in SSc, but often clinically occult.

AIM OF THE STUDY

To analyze possible associations of left ventricular (LV) myocardial function with coronary flow reserve (CFR) and endothelial function in asymptomatic patients with SSc.

METHODS

30 healthy patients and 33 age- and sex-comparable asymptomatic patients classified as having either diffuse (18 patients) or limited form (15 patients) of SSc underwent standard Doppler Echo, Doppler myocardial imaging, Strain rate imaging of interventricular septum and LV lateral wall, transthoracic CFR of left anterior descending coronary vessel (after dipyridamole infusion), and brachial artery vasodilatation measurement (Vivid 7, GE Medical Systems Inc).

RESULTS

LV diameters and ejection fraction were comparable between the two groups, while systolic pulmonary pressure (P < 0.001) was increased in SSc. By chest-CT, 15 SSc patients showed interstitial pulmonary fibrosis. Serological antibodies analysis detected anti-centromere pattern in 14 SSc patients, and anti Scl-70 in 19 patients. In SSc, LV myocardial early diastolic peak velocity, peak systolic strain rate and strain were both reduced in basal and middle interventricular septum, and in basal and middle LV lateral wall. Both CFR (P < 0.0001) and endothelial flow-mediated dilatation (P < 0.001) were significantly lower in SSc patients. By stepwise forward multivariate analyses, CFR (P < 0.001) and endothelial function (P < 0.001) were powerful independent determinants of middle LV strain.

CONCLUSIONS

Strain rate imaging, transthoracic CFR, and brachial artery flow-mediated dilatation are valuable noninvasive and easily repeatable tools for detecting LV myocardial and vascular involvement caused by SSc. Their combined use may be therefore useful for early identifying patients with more diffused and severe form of SSc, ideally in asymptomatic cases prior to the development of severe vasculopathy, when it may be most feasible to modify the disease process by new potential therapies.

Myocardial and vascular dysfunction in systemic sclerosis: The potential role of noninvasive assessment in asymptomatic patients

Systemic sclerosis (SSc) is a multi-system disorder characterized by widespread vascular lesions and fibrosis of skin and distinct internal organs. The aim of the present study was to analyze possible associations of left ventricular (LV) myocardial function with coronary flow reserve (CFR) and endothelial function in asymptomatic patients with SSc. Thirty healthy subjects and 33 age- and sex-comparable asymptomatic SSc patients underwent standard Doppler Myocardial Imaging, Strain Rate (SR) Imaging of interventricular septum (IVS) and LV lateral wall, transthoracic CFR of left anterior descending coronary vessel, and brachial artery vasodilatation measurement. In SSc patients, LV myocardial early diastolic peak velocity, peak systolic SR and strain were both reduced in basal and middle IVS, and in basal and middle LV lateral wall (p<0.001). In addition, both CFR (p<0.0001) and endothelial flow-mediated dilatation (p<0.001) were significantly lower in SSc patients. By stepwise forward multivariate analyses, CFR (p<0.001) and endothelial function (p<0.001) were powerful independent determinants of middle LV strain of SSc patients. In conclusion, SR Imaging, transthoracic CFR and brachial artery flow-mediated dilatation are valuable non-invasive and easy-repeatable tools for detecting early LV myocardial and vascular involvement caused by SSc.

Effect of a single IV administration of l-propionylcarnitine on myocardial microcirculation assessed by coronary flow velocity reserve measurement in patients with systemic sclerosis: A pilot study

BACKGROUND

Scleroderma-related cardiac involvement primarily affects coronary microvascular structures and function. The microvasculature disorder is responsible for impairment of coronary flow velocity reserve (CFVR), which has been reported in studies of patients with systemic sclerosis (SSc). L-propionylcarnitine (L-PC) is a metabolic substance that is associated with a beneficial effect on both microcirculation and myocyte function.

OBJECTIVE

The objective of this study was to determine whether or not CFVR was acutely improved or restored in patients with SSc after a single administration of IV L-PC.

METHODS

In this pilot study, we screened volunteers with SSc who had no clinical evidence of ischemic heart disease. CFVR was determined by a blinded investigator by evaluating the left anterior descending coronary artery (LADCA) by transthoracic echocardiography during adenosine infusion (140 microg/kg x min(-1) for 5 minutes), 30 minutes before and 15 minutes after administration of L-PC (300 mg IV in 5-minute bolus).

RESULTS

Thirty-three patients were screened for this study. Fourteen patients (mean [SD] age, 54.3 [11.2] years; mean [SD] weight, 63.8 [14.5] kg; mean [SD] height, 156.3 [8.7] cm) with SSc and no evidence of coronary heart disease were included in the study; 13 women and 1 man (4 with the diffuse cutaneous form of SSc and 10 with the limited cutaneous form). After administration of L-PC to patients with SSc, median CFVR was significantly increased from 2.60 to 3.23 (P < 0.001), whereas peak diastolic velocity in the LADCA decreased significantly at the basal evaluation (30.0 vs 26.0, P = 0.009) and significantly increased (80.0 vs 87.5, P = 0.005) during adenosine infusion. No adverse events occurred before, during, or after L-PC infusion.

CONCLUSIONS

Acute administration of L-PC was associated with a short-term beneficial effect on CFVR in this pilot study of patients with SSc. These results suggest that further, randomized, controlled, double-blind evaluation of longer-term administration to patients with SSc should be considered.

[Cardiac involvement in systemic sclerosis]

Systemic sclerosis (SS) can involve the pericardium, myocardium, conduction system, and cardiac valves. The presence of overt clinical signs of cardiac disease is a poor prognostic sign. Clinical manifestations include dyspnea, palpitations, chest pain, syncope, and symptoms of right heart failure. Prevalence of clinically symptomatic pericardial disease is 5-16%. However, ecocardiographic prevalence is 5.4- 41% and at autopsy is 33-77.5%. Patchy fibrosis is the characteristic myocardial finding in SS. Contraction band necrosis is the typical pathological finding. Important complications of fibrosis include left ventricular hypertrophy, as well as systolic and diastolic dysfunction of both ventricles. Early detection of these abnormalities is very important, mainly of the diastolic dysfunction, since it occurs before the systolic dysfunction and can predict important cardiac damage. Association of skeletal myositis with myocardial disease has been described. Patients with skeletal myositis are more likely to develop congestive heart failure, sustained symptomatic arrythmias, and cardiac sudden death. Coronary arteries are normal in systemic sclerosis, but there is no endomyocardial vessel involvement. There is an increased prevalence of arrhytmias, mainly premature atrial and ventricular contractions, as well as conduction system disease. Cardiac valvular involvement is minor in systemic sclerosis; mitral valve is the most frequently affected. Other abnormalities described in this disease include peripheral large vessels stiffness and secondary cardiac involvement due to pulmonary and systemic arterial hypertension. Cardiac involvement confers a high morbi-mortality risk in systemic sclerosis.

Angiographically proven coronary artery disease in scleroderma

OBJECTIVE

It has been suggested that macrovascular disease is more common in patients with scleroderma (SSc). We investigated the prevalence of coronary artery disease (CAD) in SSc using coronary angiography.

METHODS

Coronary angiography was performed in 172 patients with SSc and suspected CAD to examine the prevalence of significant CAD. The prevalence of CAD was estimated in the whole group and also according to age, gender and type of symptoms (typical angina, atypical angina and non-anginal pain or breathlessness). Standardized prevalence ratios (SPRs) were calculated in each symptomatic group in order to compare CAD rates amongst our observed population with those predicted using the Diamond and Forrester (D & F) probability analysis. This analysis provides an estimate of the probability of CAD based on gender, age and symptoms in subjects aged between 30-69 yrs.

RESULTS

The observed prevalence of CAD in the whole population was 22% (38/172); 17% (6/36) in males and 23% (32/136) in females. A total of 41 patients were excluded because they were outside the age range for D & F analysis. Compared with the reference population, the SPRs for CAD in the three SSc groups were: 47% (95% CI 21.7-89.9) in the typical angina group (22 patients), 50% (95% CI 13.6-128) in the atypical angina group (22 patients) and 93% (95% CI 49.4-158.8) in the non-anginal pain or breathlessness group (87 patients).

CONCLUSION

The prevalence of CAD in patients with SSc is similar and not greater to that expected in individuals without SSc.

Scleroderma heart disease

Heart disease is a frequent and often severe feature of systemic sclerosis (scleroderma). Cardiomyopathy, with ventricular diastolic dysfunction and arrhythmias, is the most important form, since it is associated with a very poor prognosis. The current challenge is to define its pattern and identify individuals at risk, but evaluation in vivo may be hard to perform. The aim of this review is to provide an update on the clinical aspects of scleroderma heart disease and the early pivotal role that coronary microcirculation dysfunction plays in its development. A discussion of the diagnostic tools now available for this frequently asymptomatic condition will be provided. Treatment options will be reviewed, even though no cure for systemic sclerosis exists, and the current therapy of diastolic dysfunction remains unsatisfactory.

Coronary angiographic findings in asymptomatic systemic sclerosis

The objective of this study was to assess coronary arterial involvement in asymptomatic systemic sclerosis (SSc) patients. Fourteen female patients with SSc (five limited and nine diffuse) were recruited for this study. All patients fulfilled the following 1980 American College of Rheumatology criteria for classification of SSc Masi et al (Arthritis Rheum 23:581-590 1980). None of them had chest pain nor electrocardiogram (ECG) changes suggestive of myocardial ischemia. All patients underwent thorough history taking, full clinical examination, routine laboratory investigations, and basic screening for conventional atherosclerotic disease risk factors. ECG and coronary catheterization were done for all patients. We detected 19 coronary angiographic abnormalities in our cohort. Three out of nine diffuse SSc patients (33.33%) had ectasia of the coronary arteries, and all of them had slow flow but none in the limited type. One patient with limited SSc showed spasm. Three out of five patients with limited type (60%) had stenosis, one of them had uncontrolled hypertension, while none of the diffuse type had. Five patients (55.55%) of the diffuse type had tortuosity, while it was found in only two patients (40%) of the limited type. Three patients (33.3%) of the diffuse type had calcification of the coronaries, while it was seen in two patients (40%) of the limited type. Pathological involvement of coronary arteries in asymptomatic SSc patients is not uncommon but not paralleled by clinical symptomatology.

Cardiac imaging techniques in systemic autoimmune diseases

Systemic autoimmune disorders are frequently associated to cardiac involvement and to a high prevalence of ischemic coronary events, often occurring at a younger age than in the normal population. Large increase in mortality is related to premature atherosclerosis with coronary artery disease and stroke in patients with connective tissue diseases. Coronary heart disease is responsible for 40-50% of the deaths of patients with rheumatoid arthritis. Transesophageal or transthoracic echocardiography are the most useful and noninvasive techniques able to detect not only valvular abnormalities, embolic sources or pulmonary hypertension, but also left ventricular systolic or diastolic dysfunction. Furthermore, the introduction of new indexes, contrast agents and software increased the accuracy of this technique. It is possible now to evaluate coronary flow reserve by transthoracic echocardiography in patients with systemic autoimmune disease in order to detect microvasculature disorder. However, an ischemic response in a symptomatic patient requires, in most cases, further evaluation with cardiac catheterization. Coronary artery imaging allows confirmation of the presence, extent and position of atheromatous lesions. More recently, other imaging modalities including magnetic resonance and computerized tomography angiography have been developed to allow imaging of the coronary arteries.

Heart involvement and systemic sclerosis

Scleroderma heart involvement (SHI) is often manifest, and virtually always present when accurately searched and holds a significant prognostic value. Myocardial involvement by patchy fibrosis (secondary to both repeated ischaemia and immunoinflammatory damage) leads to ventricular diastolic dysfunction, whereas right ventricle overload and failure may complicate pulmonary hypertension. Left ventricular systolic dysfunction is present in a minority of patients, namely those presenting atherosclerotic coronary artery disease and/or arterial hypertension, sometimes triggered by sclerodermic renal involvement. Dysrhythmias and conduction disturbances are considered an hallmark of SHI, facilitated by autonomic dysfunction. SHI is frequently linked to parenchimal and/or vascular lung disease; they determine symptom occurrence, particularly dyspnoea, fatigue, palpitations and chest pain when pericardium is affected. Accurate cardiologic baseline screening and subsequent follow-up are mandatory in all patients, initially consisting in some noninvasive diagnostic procedures: visit, electrocardiogram (EKG), chest X-ray, Doppler-echocardiography. When needed, these examinations should be integrated by EKG Holter-monitoring, cardiopulmonary stress tests, cardiac magnetic resonance imaging, nuclear studies of myocardial function and perfusion, cardiac catheterization to better estimate pulmonary hypertension, and cardiac natriuretic hormone evaluation. Several vasodilator approaches (prostacycline or NO/endothelin) may counteract the microvascular dysfunction at peripheral and cardiopulmonary level, and fight the sequelae of pulmonary hypertension.

Evaluation of the effect of nifedipine upon myocardial perfusion and contractility using cardiac magnetic resonance imaging and tissue Doppler echocardiography in systemic sclerosis

BACKGROUND

Primary myocardial involvement due to microcirculation impairment is common in systemic sclerosis (SSc). Cardiovascular magnetic resonance imaging (MRI) and tissue Doppler echocardiography (TDE) were recently shown to be more sensitive than conventional methods for the respective assessment of myocardial perfusion and contractility. Previous studies have suggested that dihydropyridine-type calcium channel blockers mitigate both myocardial perfusion and function abnormalities.

OBJECTIVE

To investigate the effects of nifedipine on myocardial perfusion by MRI and on contractility by TDE, in patients with SSc.

PATIENTS AND METHODS

18 patients with SSc without clinical heart failure and with normal pulmonary arterial pressure (14 women, 4 men; mean (SD) age 59 (9) years; mean (SD) disease duration 7 (4) years, 10 with diffuse and 8 with limited cutaneous forms) were prospectively evaluated. The MRI perfusion index, determined from time-intensity curves, and systolic and diastolic strain rate determined by TDE were assessed at baseline, after a 72 hour vasodilator washout period, and after 14 days of oral treatment with nifedipine 60 mg/day.

RESULTS

Nifedipine treatment led to a significant increase in the MRI perfusion index (mean (SD) 0.26 (0.07) v 0.19 (0.05) at baseline, p = 0.0003) and in systolic and diastolic strain rate (2.3 (0.6) v 1.5 (0.4) s(-1) at baseline, p = 0.0002, and 4.2 (1.6) v 3.0 (1.2) at baseline, p = 0.0003, respectively).

CONCLUSION

Fourteen days of treatment with nifedipine simultaneously improves myocardial perfusion and function, as evaluated by highly sensitive and quantitative methods.

The heart in systemic sclerosis

The heart is one of the major organs involved in scleroderma. Cardiac involvement can be manifested by myocardial disease, conduction system abnormalities, arrhythmias, or pericardial disease. Additionally, scleroderma renal crisis and pulmonary hypertension lead to significant cardiac dysfunction secondary to damage in the kidney and lung. This report summarizes the recent advances to further understand the types and mechanism of abnormalities in the heart in scleroderma. New cardiac technology shows significant frequencies of asymptomatic cardiac abnormalities. Further long-term studies are necessary to determine the outcome and the best approach to treatment of such abnormalities. Diastolic dysfunction has been carefully evaluated in scleroderma in recent years and appears to be more common than once realized. There is controversy as to whether this is a significant finding independent to other cardiopulmonary problems. More extensive evaluation of the conduction and the arrhythmia ablative therapy has helped manage these life-threatening complications.