SWOG S1820: A pilot randomized trial of the Altering Intake, Managing Bowel Symptoms Intervention in Survivors of Rectal Cancer

BACKGROUND

Survivors of rectal cancer experience persistent bowel dysfunction after treatments. Dietary interventions may be an effective approach for symptom management and posttreatment diet quality. SWOG S1820 was a pilot randomized trial of the Altering Intake, Managing Symptoms in Rectal Cancer (AIMS-RC) intervention for bowel dysfunction in survivors of rectal cancer.

METHODS

Ninety-three posttreatment survivors were randomized to the AIMS-RC group (N = 47) or the Healthy Living Education attention control group (N = 46) after informed consent and completion of a prerandomization run-in. Outcome measures were completed at baseline and at 18 and 26 weeks postrandomization. The primary end point was total bowel function score, and exploratory end points included low anterior resection syndrome (LARS) score, quality of life, dietary quality, motivation, self-efficacy, and positive/negative affect.

RESULTS

Most participants were White and college educated, with a mean age of 55.2 years and median time since surgery of 13.1 months. There were no statistically significant differences in total bowel function score by group, with the AIMS-RC group demonstrating statistically significant improvements in the exploratory end points of LARS (p = .01) and the frequency subscale of the bowel function index (p = .03). The AIMS-RC group reported significantly higher acceptability of the study.

CONCLUSIONS

SWOG S1820 did not provide evidence of benefit from the AIMS-RC intervention relative to the attention control. Select secondary end points did demonstrate improvements. The study was highly feasible and acceptable for participants in the National Cancer Institute Community Oncology Research Program. Findings provide strong support for further refinement and effectiveness testing of the AIMS-RC intervention.

Surgical versus non-surgical management for patients with malignant bowel obstruction (S1316): a pragmatic comparative effectiveness trial

BACKGROUND

Malignant small bowel obstruction has a poor prognosis and is associated with multiple related symptoms. The optimal treatment approach is often unclear. We aimed to compare surgical versus non-surgical management with the aim to determine the optimal approach for managing malignant bowel obstruction.

METHODS

S1316 was a pragmatic comparative effectiveness trial done within the National Cancer Trials Network at 30 hospital and cancer research centres in the USA, Mexico, Peru, and Colombia. Participants had an intra-abdominal or retroperitoneal primary cancer confirmed via pathological report and malignant bowel disease; were aged 18 years or older with a Zubrod performance status 0-2 within 1 week before admission; had a surgical indication; and treatment equipoise. Participants were randomly assigned (1:1) to surgical or non-surgical treatment using a dynamic balancing algorithm, balancing on primary tumour type. Patients who declined consent for random assignment were offered a prospective observational patient choice pathway. The primary outcome was the number of days alive and out of the hospital (good days) at 91 days. Analyses were based on intention-to-treat linear, logistic, and Cox regression models combining data from both pathways and adjusting for potential confounders. Treatment complications were assessed in all analysed patients in the study. This completed study is registered with ClinicalTrials.gov, NCT02270450.

FINDINGS

From May 11, 2015, to April 27, 2020, 221 patients were enrolled (143 [65%] were female and 78 [35%] were male). There were 199 evaluable participants: 49 in the randomised pathway (24 surgery and 25 non-surgery) and 150 in the patient choice pathway (58 surgery and 92 non-surgery). No difference was seen between surgery and non-surgery for the primary outcome of good days: mean 42·6 days (SD 32·2) in the randomised surgery group, 43·9 days (29·5) in the randomised non-surgery group, 54·8 days (27·0) in the patient choice surgery group, and 52·7 days (30·7) in the patient choice non-surgery group (adjusted mean difference 2·9 additional good days in surgical versus non-surgical treatment [95% CI -5·5 to 11·3]; p=0·50). During their initial hospital stay, six participants died, five due to cancer progression (four patients from the randomised pathway, two in each treatment group, and one from the patient choice pathway, in the surgery group) and one due to malignant bowel obstruction treatment complications (patient choice pathway, non-surgery). The most common grade 3-4 malignant bowel obstruction treatment complication was anaemia (three [6%] patients in the randomised pathway, all in the surgical group, and five [3%] patients in the patient choice pathway, four in the surgical group and one in the non-surgical group).

INTERPRETATION

In our study, whether patients received a surgical or non-surgical treatment approach did not influence good days during the first 91 days after registration. These findings should inform treatment decisions for patients hospitalised with malignant bowel obstruction.

FUNDING

Agency for Healthcare Research and Quality and the National Cancer Institute.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

Association of Surgical Treatment, Systemic Therapy, and Survival in Patients With Abdominal Visceral Melanoma Metastases, 1965-2014: Relevance of Surgical Cure in the Era of Modern Systemic Therapy

Importance

Systemic therapy for metastatic melanoma has evolved rapidly during the last decade, and patient treatment has become more complex.

Objective

To evaluate the survival benefit achieved through surgical resection of melanoma metastatic to the abdominal viscera in patients treated in the modern treatment environment.

Design, Setting, and Participants

This retrospective review of the institutional melanoma database from the John Wayne Cancer Institute at Providence St Johns Health Center, a tertiary-level melanoma referral center, included 1623 patients with melanoma diagnosed as having potentially resectable abdominal metastases before (1969-2003) and after (2004-2014) advances in systemic therapy.

Main Outcomes and Measures

Overall survival (OS).

Results

Of the 1623 patients identified in the database with abdominal melanoma metastases, 1097 were men (67.6%), and the mean (SD) age was 54.6 (14.6) years. Of the patients with metastatic melanoma, 1623 (320 [19.7%] in the 2004-2014 period) had abdominal metastases, including 336 (20.7%) with metastases in the gastrointestinal tract, 697 (42.9%) in the liver, 138 (8.5%) in the adrenal glands, 38 (2.3%) in the pancreas, 109 (6.7%) in the spleen, and 305 (18.8%) with multiple sites. Median OS was superior in surgical (n = 392; 18.0 months) vs nonsurgical (n = 1231; 7.0 months) patients (P < .001). The most favorable 1-year and 2-year OS was seen after surgery for gastrointestinal tract (52% and 41%) and liver (51% and 38%) metastases, respectively. Multivariable analysis found increasing age (hazard ratio [HR], 1.01; 95% CI, 1.00-1.01; P = .02) and the presence of ulceration (HR, 1.21; 95% CI, 1.01-1.45; P = .04) were associated with a worse OS. Alternatively, treatment with metastasectomy (HR, 0.59; 95% CI, 0.46-0.74; P < .001) and metastases involving the gastrointestinal tract (HR, 0.65; 95% CI, 0.48-0.87; P = .004) were associated with a better OS. The systemic treatment era did not significantly affect outcomes (HR, 0.82; 95% CI, 0.67-1.02; P = .15). Overall, patients with gastrointestinal tract metastases undergoing complete, curative resection derived the greatest benefit, with a median OS of 64 months.

Conclusions and Relevance

To our knowledge, this series is the largest single-institution experience with abdominal melanoma metastases, demonstrating that surgical resection remains an important treatment consideration even in the systemic treatment era.

Second Primary Melanoma: Risk Factors, Histopathologic Features, Survival, and Implications for Follow-Up

The impact on survival of a second primary melanoma (SPM) is unclear. We used our melanoma center's database to examine clinicopathologic risk factors and outcomes of stage 0 to IV cutaneous melanoma in patients with one versus two primaries. Among 12,325 patients with primary melanoma, 969 (7.86%) developed SPM. SPMs were significantly thinner than autologous primary melanomas (P = 0.01), and 451 SPM patients had better overall and melanoma-specific survival than 451 prognostically matched non-SPM patients (P < 0.0001 and 0.0001, respectively) at a median follow-up of 142.37 months. Patients with cutaneous melanoma are at high risk for development of SPM, but the development of SPM does not seem to impair survival.

Second Primary Melanoma: Risk Factors, Histopathologic Features, Survival, and Implications for Follow-Up

The impact on survival of a second primary melanoma (SPM) is unclear. We used our melanoma center's database to examine clinicopathologic risk factors and outcomes of stage 0 to IV cutaneous melanoma in patients with one versus two primaries. Among 12,325 patients with primary melanoma, 969 (7.86%) developed SPM. SPMs were significantly thinner than autologous primary melanomas ( P = 0.01), and 451 SPM patients had better overall and melanoma-specific survival than 451 prognostically matched non-SPM patients ( P < 0.0001 and 0.0001, respectively) at a median follow-up of 142.37 months. Patients with cutaneous melanoma are at high risk for development of SPM, but the development of SPM does not seem to impair survival.

Prognostic Utility of Immunoprofiling in Colon Cancer: Results from a Prospective, Multicenter Nodal Ultrastaging Trial

BACKGROUND

Retrospective data indicate that immunoprofiling of T cell markers can be prognostic in colon cancer. Prospective T cell immunoprofiling of colon cancer has not been well defined for patients whose lymph nodes are ultrastaged.

STUDY DESIGN

A prospective cohort was selected from patients enrolled in an ongoing phase II multicenter trial of nodal ultrastaging for colon cancer. Primary tumor specimens from 89 patients were analyzed by immunohistochemistry for the T cells CD3(+), CD4(+), CD8(+), and FOXP3(+). Lymphocyte populations were quantified with digital image analysis. Results were examined for their association with 5-year disease-free survival along with TNM stage and clinicopathologic variables.

RESULTS

Longer disease-free survival was associated with higher CD3(+) counts at the invasive margin (IM) (p = 0.005), higher CD8(+) counts at the tumor center (TC) and IM (p = 0.002), a lower CD4(+)/CD8(+) ratio at the TC+IM (p = 0.027), and a higher CD8(+)/FOXP3(+) ratio at the TC+IM (p = 0.020). After multivariable analysis, CD8(+) at the TC+IM (p = 0.002), the CD8(+)/FOXP3(+) ratio at the TC+IM (p = 0.004), and the number of tumor-positive lymph nodes (p = 0.003) remained significant.

CONCLUSIONS

This is the first prospective demonstration of the prognostic utility of immunoprofiling in colon cancer after nodal ultrastaging. Staging based on tumor immunoprofile can augment TNM staging and provide targets for specific immunotherapies.

Impact of Completion Lymph Node Dissection on Patients with Positive Sentinel Lymph Node Biopsy in Melanoma

BACKGROUND

Whether patients with positive SLNB should undergo complete lymph node dissection (CLND) is an important unanswered clinical question.

STUDY DESIGN

Patients diagnosed with positive SLNB at a melanoma referral center from 1991 to 2013 were studied. Outcomes of patients who underwent CLND were compared with those who did not undergo immediate CLND (observation [OBS] group).

RESULTS

There were 471 patients who had positive SLNB; 375 (79.6%) in the CLND group and 96 (20.4%) in the OBS group. The groups were similar except that the CLND group was younger and had more sentinel nodes removed. Five-year nodal recurrence-free survival was significantly better in the CLND group compared with the OBS group (93.1% vs 84.4%; p = 0.005). However, 5-year (66.4% vs 55.2%) and 10-year (59.5% vs 45.0%) distant metastasis-free survival rates were not significantly different (p = 0.061). The CLND group's melanoma-specific survival (MSS) rate was superior to that of the OBS group; 5-year MSS rates were 73.7% vs 65.5% and 10-year MSS rates were 66.8% vs 48.3% (p = 0.015). On multivariate analysis, CLND was associated with improved MSS (hazard ratio = 0.60; 95% CI, 0.40-0.89; p = 0.011) and lower nodal recurrence (hazard ratio = 0.46; 95% CI, 0.24-0.86; p = 0.016). Increased Breslow thickness, older age, ulceration, and trunk melanoma were all associated with worse outcomes. On subgroup analysis, the following factors were associated with better outcomes from CLND: male sex, nonulcerated primary, intermediate thickness, Clark level IV or lower extremity tumors.

CONCLUSIONS

Treatment of positive SLNB with CLND was associated with improved MSS and nodal recurrence rates. Follow-up beyond 5 years was needed to see a significant difference in MSS rates.

Rapunzel syndrome due to ingested hair extensions: Surgical and psychiatric considerations

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Consuming hair extensions can lead to intestinal obstruction.

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Massive gastric trichobezoar extending into the duodenum is termed Rapunzel syndrome.

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Rapunzel syndrome often requires surgical intervention.

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Patients with Rapunzel syndrome require close psychiatric follow-up.

Introduction

Rapunzel syndrome is a unique clinical manifestation of trichotillomania and trichophagia. The resulting gastric trichobezoar can be massive and necessitate surgical extraction.

Presentation of case

We present a case involving a 15 year-old female with a known history of trichotillomania. The patient possessed symptoms of nausea and early satiety, and admitted that she had recently consumed a large number of hair extensions. Computed tomography imaging revealed a massive gastric bezoar not amenable to endoscopic extraction. The patient underwent surgical laparotomy, and a large gastric trichobezoar was removed through an anterior gastrotomy. The trichobezoar extended past the pylorus into the duodenum, thus confirming a diagnosis of Rapunzel syndrome.

Discussion

Trichobezoars formed from the consumption of hair extensions is a rare cause of Rapunzel syndrome. Surgical extraction is often necessitated due to the sheer size of the gastric bezoar that results from consuming hair extensions. If not previously established, psychiatric consultation should be pursued in the immediate post-operative course as these patients may require pharmacologic management along with behavioral therapy to avoid further episodes of trichotillomania.

Conclusion

This case presents a unique and modern manifestation of Rapunzel syndrome. Surgical treatment most often is required when a patient presents with a massive gastric trichobezoar. Regular post-operative psychiatric follow-up is necessary to prevent recurrent episodes.

Hepatic hemorrhage as a consequence of rapid response to combined targeted therapy in metastatic melanoma

A middle-aged female with metastatic melanoma was found to have hemoperitoneum after starting systemic therapy with the BRAF and MEK inhibitors dabrafenib and trametinib. Etiology proved to be bleeding from a known hepatic metastasis. The patient was managed conservatively and eventually resumed systemic therapy with ongoing response. This case serves to illustrate the possible deleterious effects of rapid tumor response after initiation of targeted systemic therapy in patients with metastatic melanoma.

Adrenalectomy for Metastatic Melanoma: Current Role in the Age of Nonsurgical Treatments

Surgical resection of metastases to the adrenal gland can improve overall survival of patients with stage IV melanoma, but its relative value with respect to current nonsurgical therapies is unknown. We hypothesized that surgery remains an optimal first-line treatment approach for resectable adrenal metastases. A search of our institution's prospectively collected melanoma database identified stage IV patients treated for adrenal metastases between January 1, 2000, and August 11, 2014. The 91 study patients had a mean age of 60.3 years at diagnosis of adrenal metastasis and 24 had undergone adrenalectomy. Improved survival was associated with an unknown primary lesion, surgical resection, and nonsurgical therapies. Median overall survival from diagnosis of adrenal metastases was 29.2 months with adrenalectomy versus 9.4 months with nonoperative treatment. Adrenalectomy, either as complete metastasectomy or targeted to lesions resistant to systemic therapy, is associated with improved long-term survival in metastatic melanoma.

Adrenalectomy for Metastatic Melanoma: Current Role in the Age of Nonsurgical Treatments

Surgical resection of metastases to the adrenal gland can improve overall survival of patients with stage IV melanoma, but its relative value with respect to current nonsurgical therapies is unknown. We hypothesized that surgery remains an optimal first-line treatment approach for resectable adrenal metastases. A search of our institution's prospectively collected melanoma database identified stage IV patients treated for adrenal metastases between January 1, 2000, and August 11, 2014. The 91 study patients had a mean age of 60.3 years at diagnosis of adrenal metastasis and 24 had undergone adrenalectomy. Improved survival was associated with an unknown primary lesion, surgical resection, and nonsurgical therapies. Median overall survival from diagnosis of adrenal metastases was 29.2 months with adrenalectomy versus 9.4 months with nonoperative treatment. Adrenalectomy, either as complete metastasectomy or targeted to lesions resistant to systemic therapy, is associated with improved long-term survival in metastatic melanoma.

Attitudes and Perceptions of Surgical Oncology Fellows on ACGME Accreditation and the Complex General Surgical Oncology Certification

BACKGROUND

With the first qualifying examination administered September 15, 2014, complex general surgical oncology (CGSO) is now a board-certified specialty. We aimed to assess the attitudes and perceptions of current and future surgical oncology fellows regarding the recently instituted Accreditation Council for Graduate Medical Education (ACGME) accreditation.

METHODS

A 29-question anonymous survey was distributed to fellows in surgical oncology fellowship programs and applicants interviewing at our fellowship program.

RESULTS

There were 110 responses (79 fellows and 31 candidates). The response rate for the first- and second-year fellows was 66 %. Ninety-percent of the respondents were aware that completing an ACGME-accredited fellowship leads to board eligibility in CGSO. However, the majority (80 %) of the respondents stated that their decision to specialize in surgical oncology was not influenced by the ACGME accreditation. The fellows in training were concerned about the cost of the exam (90 %) and expressed anxiety in preparing for another board exam (83 %). However, the majority of the respondents believed that CGSO board certification will be helpful (79 %) in obtaining their future career goals. Interestingly, candidate fellows appeared more focused on a career in general complex surgical oncology (p = 0.004), highlighting the impact that fellowship training may have on organ-specific subspecialization.

CONCLUSIONS

The majority of the surveyed surgical oncology fellows and candidates believe that obtaining board certification in CGSO is important and will help them pursue their career goals. However, the decision to specialize in surgical oncology does not appear to be motivated by ACGME accreditation or the new board certification.

Gastrointestinal metastases from melanoma: Does surgical resection improve survival when performed in combination with immunotherapy?

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Background: Prior studies have shown the benefits of metastasectomy and more recently, immunotherapy, in Stage IV melanoma. We report the largest series of gastrointestinal (GI) melanoma metastases, in order to clarify the role of surgical resection in the setting of systemic treatment options. Methods: A review of our institutional melanoma database identified all patients with hollow viscus GI metastases diagnosed between 1971 and 2013. Patient age and sex; primary tumor location, thickness and ulceration; GI-metastasis free interval; and types of treatment were analyzed. The primary endpoint was melanoma-specific survival (MSS), measured from the diagnosis of GI metastases. Survival analyses compared combination therapy to immunotherapy (i.e. vaccine, interleukin-2, interferon, ipilimumab) or surgery alone. Operative patients were further stratified by surgical intent (curative or palliative). Results: The 393 study patients had a median GI-metastasis free interval of 49.5 (0 – 416.0) months from the initial diagnosis; their mean age at GI metastases was of 53.5 ± 14.1 years. Median MSS was 20.0 months with surgery plus immunotherapy (n=160), 13.0 months with surgery alone (n=111), 8.0 months with immunotherapy alone (n=64), and 5.0 months with neither treatment (n=58) (p<0.001). By multivariable analysis, age at GI metastasis diagnosis (HR=1.014; p=.014), truncal melanoma site (HR=1.659; p=.017), immunotherapy (HR=0.675; p=.030), and metastasectomy (HR=0.544; p<.001) were significant predictors of MSS. Surgical intent was known in 98 patients: curative surgery had a median MSS of 30.0 months (n=49) and palliative surgery had a median MSS of 12.0 months (n=49) (p=.015). Conclusions: Treatment of GI melanoma metastases should use a combination of metastasectomy and immunotherapy, instead of either modality alone. Select patients are likely to obtain an enhanced benefit from GI metastasectomy, specifically curative surgery, in the setting of newer immunotherapy options.

Pyruvate-enriched resuscitation protects hindlimb muscle from ischemia-reperfusion injury

BACKGROUND

Tourniquets impose ischemia on distal musculature. Resuscitation with pyruvate, an energy substrate and antioxidant, may ameliorate muscle ischemia-reperfusion injury.

METHODS

After goats were exsanguinated to lower mean arterial pressure to 48 mmHg, femoral vessels were occluded for 90 minutes to impose hindlimb ischemia. Lactate Ringer's (LR) or pyruvate Ringer's (PR) solution was infused from 30 minutes ischemia until 30 minutes reperfusion. Pro- and antiapoptotic proteins and injury markers were measured in gastrocnemius at 4 hours reperfusion.

RESULTS

Pro-oxidant NADPH oxidase activity and nitrotyrosine content, a footprint of nitrosative stress, doubled, and poly (ADP-ribose) polymerase cleavage, an early apoptotic event, increased 80% in LR-resuscitated vs. sham muscle, but PR prevented these increases. Antiapoptotic Bcl-X(L) content fell in LR-treated vs. sham and PR-treated muscle. Water content increased in LR- but not PR-resuscitated muscle.

CONCLUSIONS

LR resuscitation imposed oxido-nitrosative stress and initiated proapoptotic mechanisms, while PR blunted these harmful consequences of muscle ischemia-reperfusion.

Pyruvate-enriched cardioplegia suppresses cardiopulmonary bypass-induced myocardial inflammation

BACKGROUND

Cardiopulmonary bypass-induced oxidative stress initiates inflammation that can damage the myocardium. This study tested whether cardioplegia enriched with the intermediary metabolite and antioxidant pyruvate dampens postbypass myocardial inflammation.

METHODS

Pigs were maintained on cardiopulmonary bypass while their hearts were arrested for 60 minutes with 4:1 blood:crystalloid cardioplegia, in which the crystalloid contained 188 mM glucose ± 24 mM pyruvate. Pigs were weaned from bypass after 30 minutes of whole blood reperfusion and recovered for 4 hours. Glutathione (GSH) and glutathione disulfide (GSSG) were measured in coronary sinus plasma to indirectly monitor myocardial GSH redox state (GSH/GSSG). Left ventricular myocardium was sampled 4 hours after cardiopulmonary bypass for analyses of C-reactive protein, matrix metalloproteinases 2 and 9 and tissue inhibitor of metalloproteinase-2 (TIMP-2), and to assess neutrophil infiltration by histology and myeloperoxidase assay.

RESULTS

Coronary sinus GSH/GSSG fell 70% after cardiopulmonary bypass with control cardioplegia, but pyruvate cardioplegia produced a robust increase in coronary sinus GSH/GSSG that persisted for 4 hours after bypass. Myocardial C-reactive protein content increased 5.6-fold after control bypass, and neutrophil infiltration and myeloperoxidase activity also increased, but pyruvate-fortified cardioplegia prevented these inflammatory effects. Control cardioplegia lowered myocardial TIMP-2 content by 59% and increased matrix metalloproteinase-9 activity by 35% versus nonbypass sham values, but pyruvate cardioplegia increased TIMP-2 content ninefold versus control cardioplegia and prevented the increase in matrix metalloproteinase-9. Matrix metalloproteinase-2 was not affected by bypass ± pyruvate.

CONCLUSIONS

Pyruvate-enriched cardioplegia dampens cardiopulmonary bypass-induced myocardial inflammation. Increased GSH/GSSG and TIMP-2 may mediate pyruvate's effects.

Pyruvate-fortified cardioplegia evokes myocardial erythropoietin signaling in swine undergoing cardiopulmonary bypass

Pyruvate-fortified cardioplegia protects myocardium and hastens postsurgical recovery of patients undergoing cardiopulmonary bypass (CPB). Pyruvate reportedly suppresses degradation of the alpha-subunit of hypoxia-inducible factor-1 (HIF-1), an activator of the gene encoding the cardioprotective cytokine erythropoietin (EPO). This study tested the hypothesis that pyruvate-enriched cardioplegia evoked EPO expression and mobilized EPO signaling mechanisms in myocardium. Hearts of pigs maintained on CPB were arrested for 60 min with 4:1 blood-crystalloid cardioplegia. The crystalloid component contained 188 mM glucose + or - 24 mM pyruvate. After 30-min cardiac reperfusion with cardioplegia-free blood, the pigs were weaned from CPB. Left ventricular myocardium was sampled 4 h after CPB for immunoblot assessment of HIF-1alpha, EPO and its receptor, the signaling kinases Akt and ERK, and endothelial nitric oxide synthase (eNOS), an effector of EPO signaling. Pyruvate-fortified cardioplegia stabilized arterial pressure post-CPB, induced myocardial EPO mRNA expression, and increased HIF-1alpha, EPO, and EPO-R protein contents by 60, 58, and 123%, respectively, vs. control cardioplegia (P < 0.05). Pyruvate cardioplegia also increased ERK phosphorylation by 61 and 118%, respectively, vs. control cardioplegia-treated and non-CPB sham myocardium (P < 0.01), but did not alter Akt phosphorylation. Nitric oxide synthase (NOS) activity and eNOS content fell 32% following control CPB vs. sham, but pyruvate cardioplegia prevented these declines, yielding 49 and 80% greater NOS activity and eNOS content vs. respective control values (P < 0.01). Pyruvate-fortified cardioplegia induced myocardial EPO expression and mobilized the EPO-ERK-eNOS mechanism. By stabilizing HIF-1alpha, pyruvate-fortified cardioplegia may evoke sustained activation of EPO's cardioprotective signaling cascade in myocardium.