Atrial Fibrillation Ablation Success Rate - A Retrospective Multicenter Study.

Atrial fibrillation (AF) has become a major health and economic burden. Pulmonary veins isolation (PVI) based ablation for rhythm control of AF is well established. Furthermore, recent studies show its superiority over anti-arrhythmic therapy. However, most of these studies were performed in highly experienced centers, that may not necessarily reflect real world outcomes. We evaluated the outcome (success rate and complications) of 300 consecutive procedures, performed on 291 patients (during 2014-2015) of a major HMO. All had undergone PVI for AF by experienced electrophysiologists in 8 medical centers (85% RF technique). Data were retrospectively collected using computerized medical records. Variables included demographic and clinical characteristics, acute procedural success and complications, long term success rate based on multiple ECGs and Holter monitoring. The average age was 63 years, 61% were male, 79% had paroxysmal AF. Sinus rhythm at 2 years was considered success. The overall success rate of maintaining sinus rhythm at 2 years was 56%. Success rate correlated significantly with age and standard risk factors. Those patients in whom the index procedure was the first ablation, success rate was 78%. Sixty-one patients underwent a second ablation with success rate of 64%, 32 underwent a 3rd/4th procedure with success rate of 56%. The probability to be in sinus rhythm after 2 years regardless of the number of ablations was 78%. Thirty-five percent of the patients were still on anti-arrhythmic therapy at 2 years post procedure. Complication rate was 6.6% (2.5% serious), among them 2 deaths, 1 procedure related. PVI in a real-world large unselected population is a valid therapeutic option for AF with an overall 2-year success rate of 56%. In our group higher complication rate was observed compared to the reported rate in the literature. The use of cryo-ablation for PVI and further improvements in both technique and experience may improve both efficacy and safety profile.

The effect of hyperbaric oxygenation therapy on myocardial function.

Hyperbaric oxygenation therapy is successfully implemented for the treatment of several disorders. Data on the effect of hyperbaric oxygenation on echocardiographic parameters in asymptomatic patients is limited. The current study sought to evaluate the effect of hyperbaric oxygenation therapy on echocardiographic parameters in asymptomatic patients. Thirty-one consecutive patients underwent a 60-sessions course of hyperbaric oxygenation therapy in an attempt to improve cognitive impairment. In all subjects, echocardiography examination was performed before and after a course of hyperbaric oxygenation therapy. Conventional and speckle tracking imaging parameters were calculated and analyzed. The mean age was 70 ± 9.5 years, 28 [90%] were males. History of coronary artery disease was present in 12 [39%]. 94% suffered from hypertension, 42% had diabetes mellitus. Baseline wall motion abnormalities were found in eight patients, however, global ejection fraction was within normal limits. During the study, ejection fraction [EF], increased from 60.71 ± 6.02 to 62.29 ± 5.19%, p = 0.02. Left ventricular end systolic volume [LVESV], decreased from 38.08 ± 13.30 to 35.39 ± 13.32 ml, p = 0.01. Myocardial performance index [MPi] improved, from 0.29 ± 0.07 to 0.26 ± 0.08, p = 0.03. Left ventricular [LV] global longitudinal strain increased from - 19.31 ± 3.17% to - 20.16 ± 3.34%, p = 0.036 due to improvement in regional strain in the apical and antero-septal segments. Twist increased from 18.32 ± 6.61° to 23.12 ± 6.35° p = 0.01, due to improvement in the apical rotation, from 11.76 ± 4.40° to 16.10 ± 5.56°, p = 0.004. Hyperbaric oxygen therapy appears to improve left ventricular function, especially in the apical segments, and is associated with better cardiac performance. If our results are confirmed in further studies, HBOT can be used in many patients with heart failure and systolic dysfunction.

Characteristics and outcomes associated with 30-day readmissions following acute coronary syndrome 2000-2013: the Acute Coronary Syndrome Israeli Survey.

BACKGROUND: Readmissions following acute myocardial infarction are associated with poor outcomes and a heavy economic burden. There are few evidence-based data on the characteristics and outcomes of patients readmitted following acute coronary syndrome. We explored the incidence and outcomes of patients readmitted after an acute coronary syndrome in the past decade. METHODS: The study population comprised all acute coronary syndrome patients who were enrolled and prospectively followed up in the biennial Acute Coronary Syndrome Israeli Survey from 2000 to 2013. Multivariate analysis identified factors independently associated with readmission and long-term mortality. RESULTS: There were 13,010 study patients, of whom 556 (4.2%) had an unplanned readmission within 30 days of the index event. Stent thrombosis during the index hospitalisation (odds ratio (OR) 8.43; 95% confidence interval (CI) 4.11-16.07; P<0.001), female sex (OR 1.34; 95% CI 1.1-1.63; P=0.003), older age (>65 years; OR 1.28; 95% CI 1.06-1.55; P=0.011), and lack of dual-antiplatelet therapy (OR 1.52; 95% CI 1.25-1.86; P<0.001) were independently associated with readmission. Readmitted patients were less likely to have been treated with guideline-directed medical therapy during hospitalisation and at discharge, and were less likely to have undergone coronary angiography. A strong trend towards decline in readmission rates following acute coronary syndrome was observed between 2000 and 2013 (P<0.001). However, the association between readmission and poor long-term outcome was more pronounced among patients readmitted during more recent years (2008-2013). CONCLUSIONS: Patients readmitted to hospital following acute coronary syndrome comprise an undertreated, high-risk cohort. Our findings indicate that despite a significant decline in readmission rates following acute coronary syndrome over the past decade, readmission within 30 days following acute coronary syndrome still portends a grave outcome.

Prevalence and Significance of Restrictive Filling Pattern in an Echocardiography Laboratory.

BACKGROUND: A cardiac restrictive filling patterns are associated with unfavorable prognoses. Cardiac interventions may change the natural history of patients. OBJECTIVES: To investigate the prevalence of restrictive filling pattern in routine echocardiographic examinations and their association with morbidity and mortality. METHODS: The clinical and echocardiographic data of patients with newly diagnosed restrictive filling pattern were analyzed and summarized. RESULTS: Among 8000 patients who underwent an echocardiographic examination in our hospital in 2013, a restrictive filling pattern was identified in 256. Of these, 134 showed a restrictive filling pattern that was newly diagnosed. Mean age was 69 years. Hypertension, diabetes, and ischemic heart disease were found in 81%, 60%, and 53%, respectively. Left ventricular ejection fraction was 42% ± 16%. Severe valvular abnormalities were found in 18%. During follow-up (29 ± 15 months), 40% of patients died. The strongest predictor of mortality (73%) was moderate or more advanced aortic stenosis, P = 0.005. Renal failure was an important independent predictor of mortality (53%, P < 0.05). A very high E/E' ratio ≥ 20, was another independent mortality predictor (50%, P < 0.03). Patients who died were less likely to have undergone cardiac interventions than those who survived (26% vs. 45%, P < 0.03). CONCLUSIONS: Prevalence of restrictive filling among echocardiographic studies is 3.2%. In a half of these, the restrictive filling pattern is a new diagnosis. Patients who are diagnosed with a new restrictive filling pattern have higher mortality rates. Patients with restrictive filling should be evaluated thoroughly for possible coronary artery or valvular heart disease.

Adjunctive laser-stimulated stem-cells therapy to primary reperfusion in acute myocardial infarction in humans: Safety and feasibility study.

BACKGROUND: Low-level laser therapy (LLLT) has photobiostimulatory effects on stem cells and may offer cardioprotection. This cell-based therapy may compliment primary percutaneous coronary intervention (PPCI) in patients with ST-segment elevation myocardial infarction (STEMI). OBJECTIVE: In this randomized control trial, our primary objective was to determine the safety and feasibility of LLLT application to the bone marrow in patients with STEMI undergoing PPCI. METHODS: We randomly assigned patients undergoing PPCI to LLLT or non-laser therapy (NLT). In the LLLT group, 100 s of laser therapy was applied to the tibia bone prior to PPCI, as well as 24 and 72 h post-PPCI. In the control group, the power source was turned off. The primary outcome was the difference in door-to-balloon (D2B) time, and additional outcomes included differences in circulating cell counts, cardiac enzymes, and left-ventricular ejection fraction (LVEF) at pre-specified intervals post-PPCI. RESULTS: Twenty-four patients were randomized to LLLT (N = 12) or NLT (N = 12). No adverse effects of the treatment were detected. The D2B time was not significantly different between the groups (41 ± 8 vs 48 ± 1 min; P = 0.73). Creatinine Phosphokinase area under the curve, was lower after LLLT (22 ± 10) compared to NLT (49 ± 12), but this was not statistically significant (P = 0.08). Troponin-T was significantly lower after LLLT (2.7 ± 1.4 ng/mL) in comparison to NLT (5.2 ± 1.8 ng/mL. P < 0.05). At 9 months, LVEF improved in both groups without a significant difference between LLLT (55 ± 9%) and NLT (52 ± 9%; P = 0.90). CONCLUSION: LLLT is a safe and feasible adjunctive cell-based therapy to PPCI that may benefit ischemic myocardium.

Usefulness of Serum Procalcitonin as a Markerfor Coexisting Infection in Patients With Acute Myocardial Infarction.

A significant proportion of patients with acute myocardial infarction (AMI) also present with clinical manifestations of inflammatory response, which may be confused with a concomitant infection. This leads to a dilemma regarding the empiric use of antibiotics. We explored if serum procalcitonin (PCT), which is known to be elevated in bacterial infections, may be utilized to rule-out bacterial infection in AMI patients. In this prospective, single center study, PCT was collected within 48 hours from AMI patients. Patients' demographic, clinical, and laboratory data were collected prospectively. Two experienced infectious diseases specialists blinded to the PCT results independently determined the presence of infection in every patient. Sensitivity, specificity, positive predictive value, negative predictive value, and the area under the receiver operating characteristic curve were calculated to determine the accuracy of PCT, fever, white blood cell (WBC) count, and C-reactive protein (CRP) levels for the diagnosis of the infection. The analysis included 230 AMI patients (age 63.0 ± 13.0 years) of whom 36 (15.6%) had coexisting infections. The best cutoff for PCT as a differentiating marker between patients with and without coexisting infection was 0.09 ng/dl (sensitivity 94.4%, specificity 85.1%, area under the curve 0.94). PCT outperformed CRP, WBC, and fever for diagnosing infection. In conclusion, compared with CRP, fever, and WBC, serum PCT had a better performance in differentiating infected from noninfected AMI patients and thus should be considered as an adjunct test when facing the dilemma of initiating empiric antibiotic in AMI patient demonstrating inflammatory signs.

Intramyocardial dissecting hematoma: Two case reports and a meta-analysis of the literature.

Until recently, diagnosis of intramyocardial dissecting hematoma (IDH) was performed during necropsy or at surgery. During the recent years, echocardiography has permitted clinical suspicion, which usually needed confirmation with magnetic resonance imaging (MRI). In this study, we tried to define clinical and imaging features of IDH and predictors of mortality. We searched the literature for proven cases of IDH and analyzed them together with 2 of our cases. A total of 40 cases of IDH (2 our original and 38 literature cases) were included. Mean age was 60. In 32 cases, IDH was a complication of myocardial infarction (MI), in 66% anterior, a mean time from symptoms to diagnosis was 9 days. Thirty-eight % underwent surgery. In-hospital mortality was 23%. Multivariate analysis showed that the strongest independent predictor of mortality (42%) was EF < 35%; in patients with age >60, mortality risk was 44%; and in the presence of MI or late diagnosis (>24 hours since symptoms started), mortality risk was 50%. In summary, IDH is a diagnostic challenge. A high level of suspicion is needed for prompt diagnosis. Management of these patients is based on individual clinical and imaging parameters. Low EF, age > 60, and late diagnosis, all are predictors of in-hospital mortality.

Speckle tracking imaging in inflammatory heart diseases.

Accurate diagnosis of acute myocarditis is important for the prognosis and risk stratification of these patients. Cardiac magnetic resonance (CMR) has become a major modality for diagnosis of myocarditis, but not widely available. In this study, we tried to evaluate regional and global longitudinal strain by speckle tracking echocardiography in patients with acute inflammatory myocardial diseases in correlation with CMR. Patients with suspected acute myocarditis were recruited prospectively. Clinical diagnosis was established based on clinical, electrocardiographic, laboratory and conventional echocardiographic data. All patients underwent CMR and repeat echocardiographic examination within 24 h of CMR. Echocardiographic examinations were analyzed offline with speckle tracking imaging software. Thirty-two patients with acute perimyocarditis and myopericarditis were included. Mean age was 29 ± 8, 30 males. All patients presented with chest pain and an abnormal electrocardiogram, in 28 ST elevation was found. Troponin was elevated in 30 and was 0.7 ± 0.5 ng/ml. Creatine kinase was 487 ± 319 U. LVEF was 56 ± 5%. Wall motion abnormalities were present in postero-lateral (53%), and inferior wall (21%). Delayed enhancement on CMR was found in 29 patients. Echocardiographic EF based on speckle tracking imaging correlated with CMR calculated EF. There was a positive correlation between the amplitude of regional strain and delayed enhancement, r = 0.52. Sensitivity and specificity of regional strain for prediction of delayed enhancement was 85 and 73% respectively. Speckle tracking imaging can help in the diagnosis of acute myocarditis when CMR is not readily available. Speckle tracking imaging based EF correlates with CMR calculated LVEF and with global strain.

Assessment and Management of Acute Severe Mitral Regurgitation in the Intensive Care Unit.

BACKGROUND AND AIM OF THE STUDY: Acute severe mitral regurgitation (MR) is a serious medical condition. Whilst clear guidelines exist regarding the management of chronic MR, acute severe MR is usually treated on an individual basis. Currently, few data exist regarding acute MR in the era of primary coronary interventions (PCI). The present study included patients admitted to the Department of Cardiology during recent years with acute severe MR of different etiologies, and an analysis of these data in the light of previous investigations. METHODS: The digital database of the present authors' hospital was searched for patients diagnosed with severe MR between 2008 and 2015. From a total of 228 patients identified, 19 with primary MR and 17 with secondary (functional) MR were admitted to the Department of Cardiology. The clinical data and outcome of these patients were analyzed. RESULTS: Among patients with MR due to acute myocardial infarction (MI), 13 had functional MR and six had MR due to mechanical complications, namely rupture of the papillary muscle or chordae tendineae. Among patients with MR not in the setting of MI, 13 had primary MR and four had functional MR. Patients with MR due to acute MI were more often in cardiogenic shock or had pulmonary edema and had a higher mortality. The strongest predictor of mortality was the presence of shock, followed by female gender, hypertension, age ≥68 years; previous MI and pulmonary edema were also predictors of mortality. In patients with acute MI and secondary MR, PCI to the culprit coronary artery was associated with a lesser degree of MR on follow up. CONCLUSIONS: Patients with severe MR are at high risk of in-hospital death. Patients with functional MR are likely to benefit from prompt PCI to the culprit artery, and for those with primary MR urgent surgery is life-saving.

Trends in the management and outcomes of patients admitted with acute coronary syndrome complicated by cardiogenic shock over the past decade: Real world data from the acute coronary syndrome Israeli survey (ACSIS).

Registries and other cohorts have demonstrated that early revascularization improve the survival of patients presenting with Cardiogenic Shock (CS) completing Aute coronary syndrome (ACS). Our aim was to describe the change in the clinical characteristics of these patients and their management and their outcome. The study population comprised 224 patients who were admitted with ACS complicated by cardiogenic shock who were enrolled in the prospective biannual Acute Coronary Syndrome Israeli Surveys (ACSIS) between 2000 and 2013 (1.7% of all patients admitted with ACS during the study period). Survey periods were categorized as early (years 2000-2004) and late (year 2006-2013).The rate of cardiogenic shock complicated ACS declined from 1.8% between the years 2000-2004 to 1.5% during the years 2006-2013. The clinical presentation in both the early and late groups was similar. During the index hospitalization primary percutaneous coronary intervention (PPCI) was more frequently employed during the late surveys [31% vs. 58% (p<0.001)], while fibrinolysis therapy was not used in the late surveys group [27% vs. 0.0% (p=<0.001)]. Compared to patients enrolled in the early surveys, those enrolled in the late survey group experienced significantly lower mortality rates at 7-days (44% vs. 30%, respectively; p=0.03). However, this difference was no longer statistically significant at 30-days (52.8% vs. 46.4%, respectively, p=0.34) and 1-year (63% vs. 53.2%, respectively, p=0.14). Similarly, the rate of major adverse cardiac events (MACE) at 30-days was similar between the two groups (57.4% vs. 47.4%, respectively, p=0.13).Our findings indicate that patients admitted with ACS complicated by cardiogenic shock still experience very high rates of MACE and mortality during follow-up, despite a significant increase in the use of PPCI in this population over the past decade.

When Cardioversion May Be Complicated.

BACKGROUND: In recent years cardioversion of atrial fibrillation has become a routine procedure, enabling symptomatic functional improvement in most cases. However, some patients develop complications after cardioversion. Identifying these individuals is an important step toward improving patient outcome. OBJECTIVES: To characterize those patients who may not benefit from cardioversion or who may develop complications following cardioversion. METHODS: We retrospectively analyzed 186 episodes of cardioversion in 163 patients with atrial fibrillation who were admitted to our cardiology department between 2008 and 2013 based on their clinical and echocardiographic data. Patients were divided into two groups: those with uncomplicated cardioversion, and those who developed complications after cardioversion. RESULTS: Of the 186 episodes, cardioversion was done in 112 men (60%) and 74 women (40%), P < 0.00001. Complications after cardioversion occurred in 25 patients (13%). These patients were generally older (72 vs. 65 years, P < 0.01), were more often diabetic (52% vs. 27%, P = 0.005), had undergone emergency cardioversion (64% vs. 40%, P = 0.01), had left ventricular hypertrophy (left ventricular mass 260 vs. 218 g, P = 0.01), had larger left atrium (left atrial volume 128 vs. 102 ml, P < 0.009), and more often died from complications of cardioversion (48% vs. 16%). They had significant mitral regurgitation (20% vs. 4%, P = 0.03) and higher pulmonary artery pressure (50 vs. 42 mm Hg, P < 0.02). CONCLUSIONS: People with complications after cardioversion tend to be older, are more often diabetic and more often have severe mitral regurgitation. In these patients, the decision to perform cardioversion should consider the possibility of complications.

Routine Laboratory Indices as Predictor of Neurological Recovery in Post-Resuscitation Syndrome Patients Treated with Therapeutic Hypothermia.

BACKGROUND: Hypothermia is associated with improved outcome in selected survivors of cardiac arrest but no single metric enables proper prediction of neurological outcome. OBJECTIVES: To explored the association between routine laboratory indices of patients treated by hypothermia for cardiac arrest and their neurological outcome. METHODS: We retrospectively collected data from survivors of cardiac arrest treated with hypothermia for 24 hours and grouped them according to their neurological outcome to either "poor" or "favorable". Routine laboratory indices were collected at constant time intervals up to one week of admission. A comparison between the laboratory values in both groups was performed. RESULTS: Between May 2008 to November 2011, 41 consecutive patients with a mean age of 54.3 ± 16.7 years were included in this study. No significant correlation was found between routine laboratory indices and the neurological outcome. The temporal trend of decay in the serum glucose values and the ratio of polymorphonuclears to white blood cells during the first 72 hours after admission was steeper in the favorable outcome group (P for trend < 0.05). CONCLUSIONS: No single routine laboratory index was associated with neurological outcome of survivors of cardiac arrest treated with hypothermia. The temporal trends in both serum glucose and polymorphonuclear ratio signal a more intense inflammatory response associated with poor outcome.

Speckle Tracking Imaging in Normal Stress Echocardiography.

OBJECTIVES: Exercise stress echocardiography is a widely used modality for the diagnosis and follow-up of patients with coronary artery disease. During the last decade, speckle tracking imaging has been used increasingly for accurate evaluation of cardiac function. This work aimed to assess speckle-tracking imaging parameters during nonischemic exercise stress echocardiography. METHODS: During 2011 to 2014 we studied 46 patients without history of coronary artery disease, who completed exercise stress echocardiography protocol, had normal left ventricular function, a nonischemic response, and satisfactory image quality. These exams were analyzed with speckle-tracking imaging software at rest and at peak exercise. Peak strain and time-to-peak strain were measured at rest and after exercise. Clinical follow-up included a telephone contact 1 to 3 years after stress echo exam, confirming freedom from coronary events during this time. RESULTS: Global and regional peak strain increased following exercise. Time-to-peak global and regional strain and time-to-peak strain adjusted to the heart rate were significantly shorter in all segments after exercise. Rest-to-stress ratio of time-to-peak strain adjusted to the heart rate was 2.0 to 2.8. CONCLUSIONS: Global and regional peak strain rise during normal exercise echocardiography. Peak global and regional strain occur before or shortly after aortic valve closure at rest and after exercise, and the delay is more apparent at the basal segments. Time-to-peak strain normally shortens significantly during exercise; after adjustment to heart rate it shortens by a ratio of 2.0 to 2.8. These data may be useful for interpretation of future exercise stress speckle-tracking echocardiography studies.

Detection of small subendocardial infarction using speckle tracking echocardiography in a rat model.

BACKGROUND: It is challenging to detect small nontransmural infarcts visually or automatically. As it is important to detect myocardial infarction (MI) at early stages, we tested the hypothesis that small nontransmural MI can be detected using speckle tracking echocardiography (STE) at the acute stage. METHODS: Minimal nontransmural infarcts were induced in 18 rats by causing recurrent ischemia-reperfusion of the left anterior descending (LAD) coronary artery, followed by a 30-min ligation and by reperfusion. A week later, the scar size was measured by histological analysis. Each rat underwent three echocardiography measurements: at baseline, 1 day post-MI, and 1 week post-MI. To measure the peak circumferential strain (CS), peak systolic CS, radial strain (RS), and time-to-peak (TTP) of the CS, short-axis view of the apex was analyzed by a STE program. The TTP was normalized by the duration of the heart cycle to create percent change of heart cycle. RESULTS: Histological analysis after 1 week showed scar size of 4±6% at the anterior wall. At 24 h post-MI, the peak CS, peak systolic CS, and RS were reduced compared to baseline at the anterior wall due to the MI, and at the adjacent segments-the anterior septum and lateral wall, due to stunning (P<.05). However, only the anterior wall, the genuine damaged segment, showed prolonged TTP vs baseline (baseline 36%, 24 h 48%, P<.05). CONCLUSION: The TTP of the CS can distinguish between regions adjacent to MI (stunned or tethered) and MI, even in small nontransmural infarcts.

Comparison of Noninvasively and Invasively Managed Patients, With or Without Revascularization in Non-ST Elevation Myocardial Infarction (from the Acute Coronary Syndrome Israeli Survey).

Patients with non-ST elevation myocardial infarction who are managed noninvasively at presentation or are catheterized but without revascularization represent a heterogeneous and understudied population. We evaluated the clinical characteristics, management strategies, and outcomes of patients with non-ST elevation myocardial infarction (NSTEMI) who were enrolled in the prospective biannual Acute Coronary Syndrome Israeli Surveys from 2004 to 2013. Patients were divided into 3 groups: no catheterization (no angio), catheterization with revascularization (angio-revascularized), and catheterization without revascularization (angio-nonrevascularized) groups. The study included 3,198 patients with NSTEMI. Coronary angiography was performed in 2,525 (79%) during the index hospitalization, of whom 1899 (59%) underwent revascularization. Evidence-based therapies were administered during the index hospitalization at a significantly higher rate to those in the angio-revascularized group compared with the other 2 groups. Multivariate analysis showed that compared with those in the angio-revascularized and angio-nonrevascularized groups, patients in the no angio group experienced a significantly higher risk for 1-year mortality (hazard ratio 2.04 [p ≤0.0001] and 1.21 [p = 0.01], respectively). The risk associated with no revascularized was consistent in each risk subset analyzed, including an older age, and increased creatinine levels. In conclusion, our data, from a large real-world contemporary experience, suggest that patients with NSTEMI who do not undergo coronary revascularization during the index hospitalization represent a greater risk and undertreated group with increased risk for long-term mortality.

Low-Level Laser Therapy to the Bone Marrow Reduces Scarring and Improves Heart Function Post-Acute Myocardial Infarction in the Pig.

OBJECTIVE: Cell therapy for myocardial repair is one of the most intensely investigated strategies for treating acute myocardial infarction (MI). The aim of the present study was to determine whether low-level laser therapy (LLLT) application to stem cells in the bone marrow (BM) could affect the infarcted porcine heart and reduce scarring following MI. METHODS: MI was induced in farm pigs by percutaneous balloon inflation in the left coronary artery for 90 min. Laser was applied to the tibia and iliac bones 30 min, and 2 and 7 days post-induction of MI. Pigs were euthanized 90 days post-MI. The extent of scarring was analyzed by histology and MRI, and heart function was analyzed by echocardiography. RESULTS: The number of c-kit+ cells (stem cells) in the circulating blood of the laser-treated (LT) pigs was 2.62- and 2.4-fold higher than in the non-laser-treated (NLT) pigs 24 and 48 h post-MI, respectively. The infarct size [% of scar tissue out of the left ventricle (LV) volume as measured from histology] in the LT pigs was 3.2 ± 0.82%, significantly lower, 68% (p < 0.05), than that (16.6 ± 3.7%) in the NLT pigs. The mean density of small blood vessels in the infarcted area was significantly higher [6.5-fold (p < 0.025)], in the LT pigs than in the NLT ones. Echocardiography (ECHO) analysis for heart function revealed the left ventricular ejection fraction in the LT pigs to be significantly higher than in the NLT ones. CONCLUSIONS: LLLT application to BM in the porcine model for MI caused a significant reduction in scarring, enhanced angiogenesis and functional improvement both in the acute and long term phase post-MI.