HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Donato D’Agostino Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bortone, A. S. Articles by de Luca Tupputi Schinosa, L. Search for Related Content PubMed PubMed Citation Articles by Bortone, A. S. Articles by de Luca Tupputi Schinosa, L.

Ann Thorac Surg 2000;70:1134-1138
© 2000 The Society of Thoracic Surgeons

---

Supplement: cardiothoracic techniques & technologies

Inflammatory response and angiogenesis after percutaneous transmyocardial laser revascularization

^a Division of Cardiac Surgery, Department of Emergency and Transplantation, University of Bari School of Medicine, Bari, Italy
^b Institute of Nuclear Medicine, University of Bari School of Medicine, Bari, Italy

Address reprint requests to Dr Bortone, Haemodynamic Laboratory, Division of Cardiac Surgery, University of Bari, Ospedale Consorziale - Policlinico P.zza G. Cesare, 11, 70124 Bari, Italy
e-mail: emobort{at}libero.it

Presented at the Sixth Annual Meeting of Cardiothoracic Techniques and Technologies 2000, Fort Lauderdale, FL, Jan 27–29, 2000.

	Abstract

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Background. The aim of our study was to investigate the inflammatory response immediately after percutaneous transmyocardial laser revascularization (PTMR) along with the underlying mechanism of angiogenesis.

Methods. Patients with angina pectoris underwent coronary angiography and were divided into two groups. Group A (n = 10) included patients with obstructed vessels who received PTMR, whereas group B (n = 5) comprised patients who had normal coronary arteries. Blood levels of neutrophils, procalcitonin, troponin-I, myoglobin, and creatine kinase (CK) mass were evaluated in each patient before angiography and monitored up to 48 hours after the procedure. Six patients were injected with ^99mTc-leukoscan approximately 60 to 90 minutes after PTMR. During the 240 to 300 minutes after the radionuclide administration, single photon emission tomography (SPET) was performed and compared with conventional ^99mTc-sestamibi-SPET.

Results. A significant increase in blood levels of neutrophils and procalcitonin was observed in group A only (p < 0.005). A slight but significant increase of troponin-I was evident in the same group (p < 0.05), and a distinct myocardial uptake of ^99mTc-Leukoscan-SPET was observed in each patient along homologous regions treated by PTMR.

Conclusions. The increased amount of neutrophils (both circulating and inside the treated myocardial areas) along with the raised levels of procalcitonin were the immediate reactions to PTMR. This systemic and intramyocardial inflammatory response is the underlying mechanism that gives rise to angiogenesis.

	Introduction

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
It is well known that myocardial revascularization obtained by the use of laser energy is based on the idea of reproducing the reptilian heart circulation. The first application of this principle to the human heart showed that, in the normal heart exist myocardial sinusoids that create coronary circulation between the left ventricular cavity and the myocardium. In 1965, Sen and colleagues [1] proposed a new myocardial revascularization technique using transmyocardial acupuncture, although successive studies demonstrated that there were no long-term benefits because of the complete fibrosis of new channels [2, 3].

In the last two decades, several studies were reported in which surgical transmyocardial revascularization (TMR) resulted in the reduction of Canadian Cardiovascular Society (CCS) angina class in treated patients, along with an improvement in stress test tolerance [2, 4], whereas no differences were found among the survival curves of patients treated with medical therapy versus TMR [3]. Furthermore, controversial results have been reported about myocardial reperfusion evaluated by radionuclide uptake after TMR [2]. Conversely, the angiogenetic process surrounding the fibrotic channels created by this technique has been clearly documented [6].

More recently, a percutaneous approach to transmyocardial revascularization (PTMR) has been proposed [4]. It is evident from the literature that the mechanisms of action of TMR are still unclear.

Although the relief of angina has been related previously to channels created by laser treatment [1, 5], other studies currently clearly show fibrosis with complete occlusion of the new channels. Denervation of the subendocardial layer has recently been proposed as a possible explanation for the immediate relief of angina in treated patients [2]. Moreover, it has been demostrated that neoangiogenesis takes place around the laser channels [3, 7] and that numerous inflammatory cells are present around the new vessels even 4 weeks after laser treatment [5]. Nevertheless, the biological mechanisms of angiogenesis remain unknown.

The aim of this study was to verify the hypothesis that TMR causes a nonspecific inflammatory response due to the chemotactic activation of white blood cells (WBC) in the area of thermoacoustic shock generated by laser energy around the laser channels only [2, 7]. The WBC infiltration may be responsible for beginning a complex and multifactorial mechanism of angiogenesis by remodeling the treated area and mediating the release of angiogenetic factors [7]. We therefore decided to use scintigraphy combined with Leukoscan administration, a specific Fab-fragment directed to neutrophil surface antigens [8], to detect myocardial uptake and demonstrate local inflammation by observing the level of WBC acccumulation.

	Material and methods

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Patients were divided in two groups. Group A comprised 10 patients (5 men and 5 women, mean age 59.9 ± 8.9 years) complaining of angina pectoris and diagnosed as having coronary artery disease (CAD) by coronary angiography, who were treated by PTMR. Group B comprised 5 patients (3 men and 2 women, mean age 60.8 ± 12.3 years) with angina but no CAD at angiography, who served as control subjects. For all patients in both groups, blood samples were drawn before catheterization and 6, 12, 24, 48 hours after the procedure. The following data were evaluated: complete blood count and blood levels of procalcitonin, troponin I, myoglobin, and creatine kinase mass.

Patients in group A underwent two-dimensional echocardiography immediately before PTMR, to evaluate precisely left ventricular wall thickness. Only those myocardial areas with an end-diastolic wall thickness greater than 9 mm were treated. In addition, PTMR was preceded by ^99mTc-sestamibi SPET (740 + 740 MBq) at rest versus stress test, to detect reversible defects of the ischemic areas; and 201Tl-SPET (100 MBq) at rest versus redistribution, to identify reversible defects of the viable myocardium. During PTMR, standard hemodynamic criteria such as systolic, protodiastolic, and telediastolic left ventricular (LV) pressures, end-diastolic LV angiographic normalized volume (EDV), left ventricular angiographic ejection fraction, end-systolic LV angiographic normalized volume (ESV), and stroke LV angiographic normalized volume were evaluated.

For each patient, PTMR was performed safely and without complications, as previously decribed. Briefly, after local anesthesia with Xylocaine 2%, a 9F deflectable guiding catheter (Cordis Corp, Miami, FL) was inserted percutaneously in the common right femoral artery and advanced in a 0.035-inch Teflon-covered guidewire (260 cm in length), which was introduced in the left ventricle through a standard 6F pigtail catheter, also used for the two control left ventriculographies performed before and after the treatment. Thereafter, a 4F optical fiber (holmium:yttrium-aluminum garnet [YAG]; Eclipse Surgical Technologies, Inc, Sunnyvale, CA) with 2.5-J constant tip energy emission, was advanced inside the guiding catheter to reach the treated areas. The Eclipse laser emitted a burst of five pulse waves for each application; the first and second are usually performed for autocalibration, and the last three for advancing through the myocardium to obtain channels of 1 mm in diameter and from 2 to 5 mm in depth.

Blood samples from each patient were evaluated for complete blood count by automatic cell count. Immunofluorescence-detectable markers and an illuminometric quantitative test (ILMA) for procalcitonin were used to evaluate the extension of myocardial damage.

At 4 to 5 hours after Fab administration, a single photon emission tomography (^99mTc-leukoscan SPET) was performed using a -counter (GE 4000 XT, General Electrical Company, Waukesha, WI) with a low energy and high resolution collimator (64 x 64 matrix, 64 view, 25 s/view). Thereafter, 600 MBq of ^99mTc-sestamibi was injected in the antecubital vein; 30 minutes later, a chest SPET was obtained to ascertain the perfect syncronization of the two acquisitions.

The ^99mTc-leukoscan and ^99mTc-sestamibi images were stored on a 64 x 64 matrix. Filtering was achieved with a ramp-Hanning filter with a cut-off frequency of 0.83 cycle/cm. Standard back projections were used to yield transaxial sections or tomograms, each section being 1 pixel thick (approximately 0.6 cm). Tomograms obtained with the two techniques were related exactly to the same anatomical structures. Simultaneously a snake-display of eight transaxial slices obtained from the two radionuclide images was elaborated and the best LV images (visualized both by ^99mTc-sestamibi and ^99mTc-leukoscan) selected. The LV regions of interest, marked with ^99mTc-sestamibi, were traced and then superimposed on ^99mTc-leukoscan tomograms. Myocardial uptake of ^99mTc-leukoscan in the areas of PTMR execution was defined as -counter–detected areas inside the left ventricular region of interest (Fig 1).

View larger version (114K): [in this window] [in a new window]   Fig 1. The first and second rows of images correspond to the eight 99mTc-leukoscan sections; the remaining tomograms correspond to the same areas marked with 99mTc-sestamibi. The green lines delimit the region of interest of the left ventricle. The white arrows indicate the PTMR treated region in which an exact overlay of reversible perfusion defect (99mTc-sestamibi) and 99mTc-leukoscan uptake areas is evident.

	Results

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
All patients in group A (n = 10) were diagnosed with three-vessel CAD. Each patient exhibited primary risk factors for CAD (diabetes, hypertension, dislipydemia, smoking history, etc). Of the 10 patients, 7 were in angina class IV according to the Canadian Cardiovascular Society, whereas New York Heart Association class distribution was, respectively, 3 patients in class I, 6 patients in class II, and 1 patient in class III. Ejection fraction was 46.0% ± 12.8%. Fifty percent of the patients had a previous history of PTCA and CABG. Two of 10 underwent CABG only, whereas in the remaining 3 patients, distal vessel disease made both CABG and PTCA unsuitable.

The number of channels created was 10.0 ± 2.2. The treated segments were, respectively, inferior plus lateral in 3 patients, lateral in 3, inferior in 2, anterior plus inferior in 1, and anterior in 1. Despite the presence of similar risk factors and angina pectoris, all patients included in group B (n = 5) had normal coronary arteries (Table 1).

A statistically significant increase in the total quantity of leukocytes was observed only in PTMR-treated patients (p < 0.005) and, particularly, in neutrophil fractions (p < 0.005), with peaks at 12 and 24 hours, respectively, after the procedure (Fig 2, A1 and A2), whereas no significant variation was observed in control subjects. Only patients in group A exhibited a significant increase of procalcitonin blood levels (p < 0.05), with peak values 18 hours after PTMR (Fig 2, C1 and C2). Moreover, the procedure was associated with a slight but significant increase in troponin I blood levels (p < 0.05). No significant variation was reported in myoglobin or creatine kinase mass levels among the two groups (Fig 2, F1 and F2).

View larger version (39K): [in this window] [in a new window]   Fig 2. Graphic representation of leukocytes (A1 and A2, %), neutrophils (B1 and B2, %), procalcitonin (C1 and C2, ng/mL), troponin I (D1 and D2, UI), myoglobin (E1 and E2, ng/mL), and creatine kinase mass (F1 and F2, ng/mL) blood level variations between groups A and B.

	Comment

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
Although controversial data about the improvement of myocardial perfusion following PTMR treatment are diffusely reported in literature, it is commonly accepted that this technique improves the quality of life in treated patients [5]. Nevertheless, mechanisms of action related to TMR, like underlying mediators of the reported angiogenesis, remain unclear. On the other hand, it has been shown that laser channels are completely closed 12 to 24 hours after the treatment [6].

We supposed that the link between PTMR and angiogenesis is the activation of an aspecific inflammatory response due to the thermoacoustic shock generated just around the laser channels [2, 7].

We clearly demonstrated in our study that there was an immediate and aspecific inflammatory activation. Indeed, we found a significant increase in the total quantity of neutrophils in PTMR-treated patients only, whereas no variations were found in the control group. The reported response was also associated with a slight but significant increase of procalcitonin blood levels in the same group of patients. The presence of this prohormone is a sign of inflammatory cell activation [9]; for this reason, we chose its systemic evaluation, given that the observed WBC increase is also normally associated with inflammatory system activation. In our study, the slight increase in procalcitonin level is due to the fact that PTMR treatment stimulates only a regional (eg, myocardial) inflammatory reaction rather than a systemic one.

The use of ^99mTc-leukoscan [8] associated with conventional ^99mTc-sestamibi-SPET was particularly useful to demonstrate two advantages of this technique. First, the treatment of the target regions (eg, the reversible perfusion defect) and, second, the location of the activated neutrophils exclusively in treated segments. This observation gives strength to the hypothesis that a local inflammatory process represents a link between the PTMR treatment and the subsequent vessel development due to the chemotactic activity induced by neutrophils migrated within the areas of thermoacoustic shock generated only around the laser channels.

To minimize myocardial fibrosis as a consequence of laser treatment, it was necessary to reduce myocardial damage by keeping to a minimum the number of laser channels, as demonstrated by the slight increase of troponin I observed soon after the PTMR procedure. This rationale was produced by the necessity of reaching an adequate inflammatory response with a minimum myocardial damage.

This preliminary study represents only a first step, and not a definitive answer, in understanding the relationship between PTMR and angiogenesis. Further studies are necessary both to identify mediators involved in WBC regional migration and to clarify their role in vessel development inside treated areas. Our data may contribute to achieving the optimal balance between generation of new vessels in ischemic segments and myocardial functionality.

	Acknowledgments

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 
We thank Michele Sciascia, MS, and the CathLab personnel for significant contributions. We also thank Mrs Katia Surdo for secretarial assistance, and Antonio Vaira, CD, and Giovanni Nitti, BD, for blood sample analysis.

	References

Top Abstract Introduction Material and methods Results Comment Acknowledgments References

 

1. Sen P.K., Udwadia T.E., Kinare S.G., et al. Transmyocardial acupuncture. J Thorac Cardiovasc Surg 1965;50:181-189.
2. Mirhoseini M., Shelgikar S., Cayton M.M. New concepts in revascularization of the myocardium. Ann Thorac Surg 1988;45:415-420.[Abstract]
3. Whittaker P., Rakusan K., Kloner R.A. Transmural channels can protect ischemic tissue. Circulation 1996;93:143-152.[Abstract/Free Full Text]
4. Allen K.B., Dowling R.D., Fudge T.L., et al. Comparison of transmyocardial revascularization with medical therapy in patients with refractory angina. N Engl J Med 1999;341:1029-1036.[Abstract/Free Full Text]
5. Oesterle S.N., Reifart N., Meier B., et al. Laser-based percutaneous myocardial revascularization (PMR). Am J Cardiol 1998;82:659-662.[Medline]
6. Burkhoff D., Fisher P.E., Appelbaum M., et al. Histologic appearance of transmyocardial laser channels after 4 weeks. Ann Thorac Surg 1996;61:1532-1535.[Abstract/Free Full Text]
7. Pelletier M.P., Giaid A., Sivaraman S., et al. Angiogenesis and growth factor expression in a model of transmyocardial revascularization. Ann Thorac Surg 1998;66:12-18.[Abstract/Free Full Text]
8. Joseph K., Hoffken H., Bosslet K., Schorlemmer H.U. In vivo labelling of granulocytes with 99mTc anti-NCA monoclonal antibodies for imaging inflammation. Eur J Nucl Med 1988;14:367-373.[Medline]
9. Meisner M., Tschaikowsky K., Spiebl C., Schuttler J. Procalcitonin a marker or modulator of the acute immune response?. Intensive Care Med 1996;22:14.

This article has been cited by other articles:

				K. F. Welke, E. D. Peterson, M. S. Vaughan-Sarrazin, S. M. O'Brien, G. E. Rosenthal, G. J. Shook, R. S. Dokholyan, C. K. Haan, and T. B. Ferguson Jr Comparison of Cardiac Surgery Volumes and Mortality Rates Between The Society of Thoracic Surgeons and Medicare Databases From 1993 Through 2001 Ann. Thorac. Surg., November 1, 2007; 84(5): 1538 - 1546. [Abstract] [Full Text] [PDF]

				S Enomoto, M Yoshiyama, T Omura, R Matsumoto, T Kusuyama, D Nishiya, Y Izumi, K Akioka, H Iwao, K Takeuchi, et al. Microbubble destruction with ultrasound augments neovascularisation by bone marrow cell transplantation in rat hind limb ischaemia Heart, April 1, 2006; 92(4): 515 - 520. [Abstract] [Full Text] [PDF]

				J. Yoshida, K. Ohmori, H. Takeuchi, K. Shinomiya, T. Namba, I. Kondo, H. Kiyomoto, and M. Kohno Treatment of Ischemic Limbs Based on Local Recruitment of Vascular Endothelial Growth Factor-Producing Inflammatory Cells With Ultrasonic Microbubble Destruction J. Am. Coll. Cardiol., September 6, 2005; 46(5): 899 - 905. [Abstract] [Full Text] [PDF]

				J. Song, M. Qi, S. Kaul, and R. J. Price Stimulation of Arteriogenesis in Skeletal Muscle by Microbubble Destruction With Ultrasound Circulation, September 17, 2002; 106(12): 1550 - 1555. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Donato D’Agostino Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bortone, A. S. Articles by de Luca Tupputi Schinosa, L. Search for Related Content PubMed PubMed Citation Articles by Bortone, A. S. Articles by de Luca Tupputi Schinosa, L.